creation_sourcecode: // SPDX-License-Identifier: AGPL-3.0
  pragma solidity 0.8.21;
  
  
  // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
  /**
   * @dev Interface of the ERC20 standard as defined in the EIP.
   */
  interface IERC20 {
      /**
       * @dev Emitted when `value` tokens are moved from one account (`from`) to
       * another (`to`).
       *
       * Note that `value` may be zero.
       */
      event Transfer(address indexed from, address indexed to, uint256 value);
  
      /**
       * @dev Emitted when the allowance of a `spender` for an `owner` is set by
       * a call to {approve}. `value` is the new allowance.
       */
      event Approval(address indexed owner, address indexed spender, uint256 value);
  
      /**
       * @dev Returns the amount of tokens in existence.
       */
      function totalSupply() external view returns (uint256);
  
      /**
       * @dev Returns the amount of tokens owned by `account`.
       */
      function balanceOf(address account) external view returns (uint256);
  
      /**
       * @dev Moves `amount` tokens from the caller's account to `to`.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transfer(address to, uint256 amount) external returns (bool);
  
      /**
       * @dev Returns the remaining number of tokens that `spender` will be
       * allowed to spend on behalf of `owner` through {transferFrom}. This is
       * zero by default.
       *
       * This value changes when {approve} or {transferFrom} are called.
       */
      function allowance(address owner, address spender) external view returns (uint256);
  
      /**
       * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * IMPORTANT: Beware that changing an allowance with this method brings the risk
       * that someone may use both the old and the new allowance by unfortunate
       * transaction ordering. One possible solution to mitigate this race
       * condition is to first reduce the spender's allowance to 0 and set the
       * desired value afterwards:
       * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
       *
       * Emits an {Approval} event.
       */
      function approve(address spender, uint256 amount) external returns (bool);
  
      /**
       * @dev Moves `amount` tokens from `from` to `to` using the
       * allowance mechanism. `amount` is then deducted from the caller's
       * allowance.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(address from, address to, uint256 amount) external returns (bool);
  }
  
  // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
  /**
   * @dev Interface for the optional metadata functions from the ERC20 standard.
   *
   * _Available since v4.1._
   */
  interface IERC20Metadata is IERC20 {
      /**
       * @dev Returns the name of the token.
       */
      function name() external view returns (string memory);
  
      /**
       * @dev Returns the symbol of the token.
       */
      function symbol() external view returns (string memory);
  
      /**
       * @dev Returns the decimals places of the token.
       */
      function decimals() external view returns (uint8);
  }
  
  // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
  /**
   * @dev Provides information about the current execution context, including the
   * sender of the transaction and its data. While these are generally available
   * via msg.sender and msg.data, they should not be accessed in such a direct
   * manner, since when dealing with meta-transactions the account sending and
   * paying for execution may not be the actual sender (as far as an application
   * is concerned).
   *
   * This contract is only required for intermediate, library-like contracts.
   */
  abstract contract Context {
      function _msgSender() internal view virtual returns (address) {
          return msg.sender;
      }
  
      function _msgData() internal view virtual returns (bytes calldata) {
          return msg.data;
      }
  }
  
  contract ERC20 is Context, IERC20, IERC20Metadata {
      mapping(address => uint256) private _balances;
  
      mapping(address => mapping(address => uint256)) private _allowances;
  
      uint256 private _totalSupply;
  
      string private _name;
      string private _symbol;
  
      /**
       * @dev Sets the values for {name} and {symbol}.
       *
       * All two of these values are immutable: they can only be set once during
       * construction.
       */
      constructor(string memory name_, string memory symbol_) {
          _name = name_;
          _symbol = symbol_;
      }
  
      /**
       * @dev Returns the name of the token.
       */
      function name() public view virtual override returns (string memory) {
          return _name;
      }
  
      /**
       * @dev Returns the symbol of the token, usually a shorter version of the
       * name.
       */
      function symbol() public view virtual override returns (string memory) {
          return _symbol;
      }
  
      /**
       * @dev Returns the number of decimals used to get its user representation.
       * For example, if `decimals` equals `2`, a balance of `505` tokens should
       * be displayed to a user as `5.05` (`505 / 10 ** 2`).
       *
       * Tokens usually opt for a value of 18, imitating the relationship between
       * Ether and Wei. This is the default value returned by this function, unless
       * it's overridden.
       *
       * NOTE: This information is only used for _display_ purposes: it in
       * no way affects any of the arithmetic of the contract, including
       * {IERC20-balanceOf} and {IERC20-transfer}.
       */
      function decimals() public view virtual override returns (uint8) {
          return 18;
      }
  
      /**
       * @dev See {IERC20-totalSupply}.
       */
      function totalSupply() public view virtual override returns (uint256) {
          return _totalSupply;
      }
  
      /**
       * @dev See {IERC20-balanceOf}.
       */
      function balanceOf(address account) public view virtual override returns (uint256) {
          return _balances[account];
      }
  
      /**
       * @dev See {IERC20-transfer}.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - the caller must have a balance of at least `amount`.
       */
      function transfer(address to, uint256 amount) public virtual override returns (bool) {
          address owner = _msgSender();
          _transfer(owner, to, amount);
          return true;
      }
  
      /**
       * @dev See {IERC20-allowance}.
       */
      function allowance(address owner, address spender) public view virtual override returns (uint256) {
          return _allowances[owner][spender];
      }
  
      /**
       * @dev See {IERC20-approve}.
       *
       * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
       * `transferFrom`. This is semantically equivalent to an infinite approval.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       */
      function approve(address spender, uint256 amount) public virtual override returns (bool) {
          address owner = _msgSender();
          _approve(owner, spender, amount);
          return true;
      }
  
      /**
       * @dev See {IERC20-transferFrom}.
       *
       * Emits an {Approval} event indicating the updated allowance. This is not
       * required by the EIP. See the note at the beginning of {ERC20}.
       *
       * NOTE: Does not update the allowance if the current allowance
       * is the maximum `uint256`.
       *
       * Requirements:
       *
       * - `from` and `to` cannot be the zero address.
       * - `from` must have a balance of at least `amount`.
       * - the caller must have allowance for ``from``'s tokens of at least
       * `amount`.
       */
      function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
          address spender = _msgSender();
          _spendAllowance(from, spender, amount);
          _transfer(from, to, amount);
          return true;
      }
  
      /**
       * @dev Atomically increases the allowance granted to `spender` by the caller.
       *
       * This is an alternative to {approve} that can be used as a mitigation for
       * problems described in {IERC20-approve}.
       *
       * Emits an {Approval} event indicating the updated allowance.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       */
      function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
          address owner = _msgSender();
          _approve(owner, spender, allowance(owner, spender) + addedValue);
          return true;
      }
  
      /**
       * @dev Atomically decreases the allowance granted to `spender` by the caller.
       *
       * This is an alternative to {approve} that can be used as a mitigation for
       * problems described in {IERC20-approve}.
       *
       * Emits an {Approval} event indicating the updated allowance.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       * - `spender` must have allowance for the caller of at least
       * `subtractedValue`.
       */
      function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
          address owner = _msgSender();
          uint256 currentAllowance = allowance(owner, spender);
          require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
          unchecked {
              _approve(owner, spender, currentAllowance - subtractedValue);
          }
  
          return true;
      }
  
      /**
       * @dev Moves `amount` of tokens from `from` to `to`.
       *
       * This internal function is equivalent to {transfer}, and can be used to
       * e.g. implement automatic token fees, slashing mechanisms, etc.
       *
       * Emits a {Transfer} event.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `from` must have a balance of at least `amount`.
       */
      function _transfer(address from, address to, uint256 amount) internal virtual {
          require(from != address(0), "ERC20: transfer from the zero address");
          require(to != address(0), "ERC20: transfer to the zero address");
  
          _beforeTokenTransfer(from, to, amount);
  
          uint256 fromBalance = _balances[from];
          require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
          unchecked {
              _balances[from] = fromBalance - amount;
              // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
              // decrementing then incrementing.
              _balances[to] += amount;
          }
  
          emit Transfer(from, to, amount);
  
          _afterTokenTransfer(from, to, amount);
      }
  
      /** @dev Creates `amount` tokens and assigns them to `account`, increasing
       * the total supply.
       *
       * Emits a {Transfer} event with `from` set to the zero address.
       *
       * Requirements:
       *
       * - `account` cannot be the zero address.
       */
      function _mint(address account, uint256 amount) internal virtual {
          require(account != address(0), "ERC20: mint to the zero address");
  
          _beforeTokenTransfer(address(0), account, amount);
  
          _totalSupply += amount;
          unchecked {
              // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
              _balances[account] += amount;
          }
          emit Transfer(address(0), account, amount);
  
          _afterTokenTransfer(address(0), account, amount);
      }
  
      /**
       * @dev Destroys `amount` tokens from `account`, reducing the
       * total supply.
       *
       * Emits a {Transfer} event with `to` set to the zero address.
       *
       * Requirements:
       *
       * - `account` cannot be the zero address.
       * - `account` must have at least `amount` tokens.
       */
      function _burn(address account, uint256 amount) internal virtual {
          require(account != address(0), "ERC20: burn from the zero address");
  
          _beforeTokenTransfer(account, address(0), amount);
  
          uint256 accountBalance = _balances[account];
          require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
          unchecked {
              _balances[account] = accountBalance - amount;
              // Overflow not possible: amount <= accountBalance <= totalSupply.
              _totalSupply -= amount;
          }
  
          emit Transfer(account, address(0), amount);
  
          _afterTokenTransfer(account, address(0), amount);
      }
  
      /**
       * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
       *
       * This internal function is equivalent to `approve`, and can be used to
       * e.g. set automatic allowances for certain subsystems, etc.
       *
       * Emits an {Approval} event.
       *
       * Requirements:
       *
       * - `owner` cannot be the zero address.
       * - `spender` cannot be the zero address.
       */
      function _approve(address owner, address spender, uint256 amount) internal virtual {
          require(owner != address(0), "ERC20: approve from the zero address");
          require(spender != address(0), "ERC20: approve to the zero address");
  
          _allowances[owner][spender] = amount;
          emit Approval(owner, spender, amount);
      }
  
      /**
       * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
       *
       * Does not update the allowance amount in case of infinite allowance.
       * Revert if not enough allowance is available.
       *
       * Might emit an {Approval} event.
       */
      function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
          uint256 currentAllowance = allowance(owner, spender);
          if (currentAllowance != type(uint256).max) {
              require(currentAllowance >= amount, "ERC20: insufficient allowance");
              unchecked {
                  _approve(owner, spender, currentAllowance - amount);
              }
          }
      }
  
      /**
       * @dev Hook that is called before any transfer of tokens. This includes
       * minting and burning.
       *
       * Calling conditions:
       *
       * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
       * will be transferred to `to`.
       * - when `from` is zero, `amount` tokens will be minted for `to`.
       * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
       * - `from` and `to` are never both zero.
       *
       * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
       */
      function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}
  
      /**
       * @dev Hook that is called after any transfer of tokens. This includes
       * minting and burning.
       *
       * Calling conditions:
       *
       * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
       * has been transferred to `to`.
       * - when `from` is zero, `amount` tokens have been minted for `to`.
       * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
       * - `from` and `to` are never both zero.
       *
       * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
       */
      function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
  }
  
  interface IERC4626 is IERC20, IERC20Metadata {
      event Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares);
  
      event Withdraw(
          address indexed sender,
          address indexed receiver,
          address indexed owner,
          uint256 assets,
          uint256 shares
      );
  
      /**
       * @dev Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.
       *
       * - MUST be an ERC-20 token contract.
       * - MUST NOT revert.
       */
      function asset() external view returns (address assetTokenAddress);
  
      /**
       * @dev Returns the total amount of the underlying asset that is “managed” by Vault.
       *
       * - SHOULD include any compounding that occurs from yield.
       * - MUST be inclusive of any fees that are charged against assets in the Vault.
       * - MUST NOT revert.
       */
      function totalAssets() external view returns (uint256 totalManagedAssets);
  
      /**
       * @dev Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal
       * scenario where all the conditions are met.
       *
       * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
       * - MUST NOT show any variations depending on the caller.
       * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
       * - MUST NOT revert.
       *
       * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
       * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
       * from.
       */
      function convertToShares(uint256 assets) external view returns (uint256 shares);
  
      /**
       * @dev Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal
       * scenario where all the conditions are met.
       *
       * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
       * - MUST NOT show any variations depending on the caller.
       * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
       * - MUST NOT revert.
       *
       * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
       * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
       * from.
       */
      function convertToAssets(uint256 shares) external view returns (uint256 assets);
  
      /**
       * @dev Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver,
       * through a deposit call.
       *
       * - MUST return a limited value if receiver is subject to some deposit limit.
       * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.
       * - MUST NOT revert.
       */
      function maxDeposit(address receiver) external view returns (uint256 maxAssets);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given
       * current on-chain conditions.
       *
       * - MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit
       *   call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called
       *   in the same transaction.
       * - MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the
       *   deposit would be accepted, regardless if the user has enough tokens approved, etc.
       * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by depositing.
       */
      function previewDeposit(uint256 assets) external view returns (uint256 shares);
  
      /**
       * @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.
       *
       * - MUST emit the Deposit event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
       *   deposit execution, and are accounted for during deposit.
       * - MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not
       *   approving enough underlying tokens to the Vault contract, etc).
       *
       * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
       */
      function deposit(uint256 assets, address receiver) external returns (uint256 shares);
  
      /**
       * @dev Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call.
       * - MUST return a limited value if receiver is subject to some mint limit.
       * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted.
       * - MUST NOT revert.
       */
      function maxMint(address receiver) external view returns (uint256 maxShares);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given
       * current on-chain conditions.
       *
       * - MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call
       *   in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the
       *   same transaction.
       * - MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint
       *   would be accepted, regardless if the user has enough tokens approved, etc.
       * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by minting.
       */
      function previewMint(uint256 shares) external view returns (uint256 assets);
  
      /**
       * @dev Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.
       *
       * - MUST emit the Deposit event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint
       *   execution, and are accounted for during mint.
       * - MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not
       *   approving enough underlying tokens to the Vault contract, etc).
       *
       * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
       */
      function mint(uint256 shares, address receiver) external returns (uint256 assets);
  
      /**
       * @dev Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the
       * Vault, through a withdraw call.
       *
       * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
       * - MUST NOT revert.
       */
      function maxWithdraw(address owner) external view returns (uint256 maxAssets);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block,
       * given current on-chain conditions.
       *
       * - MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw
       *   call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if
       *   called
       *   in the same transaction.
       * - MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though
       *   the withdrawal would be accepted, regardless if the user has enough shares, etc.
       * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by depositing.
       */
      function previewWithdraw(uint256 assets) external view returns (uint256 shares);
  
      /**
       * @dev Burns shares from owner and sends exactly assets of underlying tokens to receiver.
       *
       * - MUST emit the Withdraw event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
       *   withdraw execution, and are accounted for during withdraw.
       * - MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner
       *   not having enough shares, etc).
       *
       * Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
       * Those methods should be performed separately.
       */
      function withdraw(uint256 assets, address receiver, address owner) external returns (uint256 shares);
  
      /**
       * @dev Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault,
       * through a redeem call.
       *
       * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
       * - MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.
       * - MUST NOT revert.
       */
      function maxRedeem(address owner) external view returns (uint256 maxShares);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their redeemption at the current block,
       * given current on-chain conditions.
       *
       * - MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call
       *   in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the
       *   same transaction.
       * - MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the
       *   redemption would be accepted, regardless if the user has enough shares, etc.
       * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by redeeming.
       */
      function previewRedeem(uint256 shares) external view returns (uint256 assets);
  
      /**
       * @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver.
       *
       * - MUST emit the Withdraw event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
       *   redeem execution, and are accounted for during redeem.
       * - MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner
       *   not having enough shares, etc).
       *
       * NOTE: some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
       * Those methods should be performed separately.
       */
      function redeem(uint256 shares, address receiver, address owner) external returns (uint256 assets);
  }
  
  // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
  /**
   * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
   * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
   *
   * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
   * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
   * need to send a transaction, and thus is not required to hold Ether at all.
   */
  interface IERC20Permit {
      /**
       * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
       * given ``owner``'s signed approval.
       *
       * IMPORTANT: The same issues {IERC20-approve} has related to transaction
       * ordering also apply here.
       *
       * Emits an {Approval} event.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       * - `deadline` must be a timestamp in the future.
       * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
       * over the EIP712-formatted function arguments.
       * - the signature must use ``owner``'s current nonce (see {nonces}).
       *
       * For more information on the signature format, see the
       * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
       * section].
       */
      function permit(
          address owner,
          address spender,
          uint256 value,
          uint256 deadline,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) external;
  
      /**
       * @dev Returns the current nonce for `owner`. This value must be
       * included whenever a signature is generated for {permit}.
       *
       * Every successful call to {permit} increases ``owner``'s nonce by one. This
       * prevents a signature from being used multiple times.
       */
      function nonces(address owner) external view returns (uint256);
  
      /**
       * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
       */
      // solhint-disable-next-line func-name-mixedcase
      function DOMAIN_SEPARATOR() external view returns (bytes32);
  }
  
  interface ITokenizedStrategy is IERC4626, IERC20Permit {
      /*//////////////////////////////////////////////////////////////
                                   EVENTS
      //////////////////////////////////////////////////////////////*/
  
      event UpdatePendingManagement(address indexed newPendingManagement);
  
      event UpdateManagement(address indexed newManagement);
  
      event UpdateKeeper(address indexed newKeeper);
  
      event UpdateEmergencyAdmin(address indexed newEmergencyAdmin);
  
      event UpdatePerformanceFee(uint16 newPerformanceFee);
  
      event UpdatePerformanceFeeRecipient(
          address indexed newPerformanceFeeRecipient
      );
  
      event UpdateProfitMaxUnlockTime(uint256 newProfitMaxUnlockTime);
  
      event StrategyShutdown();
  
      event Reported(
          uint256 profit,
          uint256 loss,
          uint256 protocolFees,
          uint256 performanceFees
      );
  
      /*//////////////////////////////////////////////////////////////
                             INITIALIZATION
      //////////////////////////////////////////////////////////////*/
  
      function init(
          address _asset,
          string memory _name,
          address _management,
          address _performanceFeeRecipient,
          address _keeper
      ) external;
  
      /*//////////////////////////////////////////////////////////////
                      NON-STANDARD 4626 OPTIONS
      //////////////////////////////////////////////////////////////*/
  
      function withdraw(
          uint256 assets,
          address receiver,
          address owner,
          uint256 maxLoss
      ) external returns (uint256);
  
      function redeem(
          uint256 shares,
          address receiver,
          address owner,
          uint256 maxLoss
      ) external returns (uint256);
  
      /*//////////////////////////////////////////////////////////////
                              MODIFIERS
      //////////////////////////////////////////////////////////////*/
  
      function isManagement(address _sender) external view returns (bool);
  
      function isKeeperOrManagement(address _sender) external view returns (bool);
  
      function isEmergencyAuthorized(
          address _sender
      ) external view returns (bool);
  
      /*//////////////////////////////////////////////////////////////
                          KEEPERS FUNCTIONS
      //////////////////////////////////////////////////////////////*/
  
      function tend() external;
  
      function report() external returns (uint256 _profit, uint256 _loss);
  
      /*//////////////////////////////////////////////////////////////
                          CONSTANTS
      //////////////////////////////////////////////////////////////*/
  
      function MIN_FEE() external view returns (uint16);
  
      function MAX_FEE() external view returns (uint16);
  
      function FACTORY() external view returns (address);
  
      /*//////////////////////////////////////////////////////////////
                              GETTERS
      //////////////////////////////////////////////////////////////*/
  
      function apiVersion() external view returns (string memory);
  
      function pricePerShare() external view returns (uint256);
  
      function totalIdle() external view returns (uint256);
  
      function totalDebt() external view returns (uint256);
  
      function management() external view returns (address);
  
      function pendingManagement() external view returns (address);
  
      function keeper() external view returns (address);
  
      function emergencyAdmin() external view returns (address);
  
      function performanceFee() external view returns (uint16);
  
      function performanceFeeRecipient() external view returns (address);
  
      function fullProfitUnlockDate() external view returns (uint256);
  
      function profitUnlockingRate() external view returns (uint256);
  
      function profitMaxUnlockTime() external view returns (uint256);
  
      function lastReport() external view returns (uint256);
  
      function isShutdown() external view returns (bool);
  
      function unlockedShares() external view returns (uint256);
  
      /*//////////////////////////////////////////////////////////////
                              SETTERS
      //////////////////////////////////////////////////////////////*/
  
      function setPendingManagement(address) external;
  
      function acceptManagement() external;
  
      function setKeeper(address _keeper) external;
  
      function setEmergencyAdmin(address _emergencyAdmin) external;
  
      function setPerformanceFee(uint16 _performanceFee) external;
  
      function setPerformanceFeeRecipient(
          address _performanceFeeRecipient
      ) external;
  
      function setProfitMaxUnlockTime(uint256 _profitMaxUnlockTime) external;
  
      function shutdownStrategy() external;
  
      function emergencyWithdraw(uint256 _amount) external;
  
      /*//////////////////////////////////////////////////////////////
                             ERC20 ADD ONS
      //////////////////////////////////////////////////////////////*/
  
      function decreaseAllowance(
          address spender,
          uint256 subtractedValue
      ) external returns (bool);
  
      function increaseAllowance(
          address spender,
          uint256 addedValue
      ) external returns (bool);
  }
  
  abstract contract BaseStrategy {
      /*//////////////////////////////////////////////////////////////
                              MODIFIERS
      //////////////////////////////////////////////////////////////*/
      /**
       * @dev Used on TokenizedStrategy callback functions to make sure it is post
       * a delegateCall from this address to the TokenizedStrategy.
       */
      modifier onlySelf() {
          _onlySelf();
          _;
      }
  
      /**
       * @dev Use to assure that the call is coming from the strategies management.
       */
      modifier onlyManagement() {
          TokenizedStrategy.isManagement(msg.sender);
          _;
      }
  
      /**
       * @dev Use to assure that the call is coming from either the strategies
       * management or the keeper.
       */
      modifier onlyKeepers() {
          TokenizedStrategy.isKeeperOrManagement(msg.sender);
          _;
      }
  
      /**
       * @dev Use to assure that the call is coming from either the strategies
       * management or the emergency admin.
       */
      modifier onlyEmergencyAuthorized() {
          TokenizedStrategy.isEmergencyAuthorized(msg.sender);
          _;
      }
  
      function _onlySelf() internal view {
          require(msg.sender == address(this), "!self");
      }
  
      /*//////////////////////////////////////////////////////////////
                              CONSTANTS
      //////////////////////////////////////////////////////////////*/
  
      /**
       * This is the address of the TokenizedStrategy implementation
       * contract that will be used by all strategies to handle the
       * accounting, logic, storage etc.
       *
       * Any external calls to the that don't hit one of the functions
       * defined in this base or the strategy will end up being forwarded
       * through the fallback function, which will delegateCall this address.
       *
       * This address should be the same for every strategy, never be adjusted
       * and always be checked before any integration with the Strategy.
       */
      address public constant tokenizedStrategyAddress =
          0xDFC8cD9F2f2d306b7C0d109F005DF661E14f4ff2;
  
      /*//////////////////////////////////////////////////////////////
                              IMMUTABLES
      //////////////////////////////////////////////////////////////*/
  
      /**
       * This variable is set to address(this) during initialization of each strategy.
       *
       * This can be used to retrieve storage data within the strategy
       * contract as if it were a linked library.
       *
       *       i.e. uint256 totalAssets = TokenizedStrategy.totalAssets()
       *
       * Using address(this) will mean any calls using this variable will lead
       * to a call to itself. Which will hit the fallback function and
       * delegateCall that to the actual TokenizedStrategy.
       */
      ITokenizedStrategy internal immutable TokenizedStrategy;
  
      // Underlying asset the Strategy is earning yield on.
      // Stored here for cheap retrievals within the strategy.
      ERC20 internal immutable asset;
  
      /**
       * @notice Used to initialize the strategy on deployment.
       *
       * This will set the `TokenizedStrategy` variable for easy
       * internal view calls to the implementation. As well as
       * initializing the default storage variables based on the
       * parameters and using the deployer for the permissioned roles.
       *
       * @param _asset Address of the underlying asset.
       * @param _name Name the strategy will use.
       */
      constructor(address _asset, string memory _name) {
          asset = ERC20(_asset);
  
          // Set instance of the implementation for internal use.
          TokenizedStrategy = ITokenizedStrategy(address(this));
  
          // Initialize the strategy's storage variables.
          _delegateCall(
              abi.encodeCall(
                  ITokenizedStrategy.init,
                  (_asset, _name, msg.sender, msg.sender, msg.sender)
              )
          );
  
          // Store the tokenizedStrategyAddress at the standard implementation
          // address storage slot so etherscan picks up the interface. This gets
          // stored on initialization and never updated.
          assembly {
              sstore(
                  // keccak256('eip1967.proxy.implementation' - 1)
                  0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc,
                  tokenizedStrategyAddress
              )
          }
      }
  
      /*//////////////////////////////////////////////////////////////
                  NEEDED TO BE OVERRIDDEN BY STRATEGIST
      //////////////////////////////////////////////////////////////*/
  
      /**
       * @dev Should deploy up to '_amount' of 'asset' in the yield source.
       *
       * This function is called at the end of a {deposit} or {mint}
       * call. Meaning that unless a whitelist is implemented it will
       * be entirely permissionless and thus can be sandwiched or otherwise
       * manipulated.
       *
       * @param _amount The amount of 'asset' that the strategy should attempt
       * to deposit in the yield source.
       */
      function _deployFunds(uint256 _amount) internal virtual;
  
      /**
       * @dev Will attempt to free the '_amount' of 'asset'.
       *
       * The amount of 'asset' that is already loose has already
       * been accounted for.
       *
       * This function is called during {withdraw} and {redeem} calls.
       * Meaning that unless a whitelist is implemented it will be
       * entirely permissionless and thus can be sandwiched or otherwise
       * manipulated.
       *
       * Should not rely on asset.balanceOf(address(this)) calls other than
       * for diff accounting purposes.
       *
       * Any difference between `_amount` and what is actually freed will be
       * counted as a loss and passed on to the withdrawer. This means
       * care should be taken in times of illiquidity. It may be better to revert
       * if withdraws are simply illiquid so not to realize incorrect losses.
       *
       * @param _amount, The amount of 'asset' to be freed.
       */
      function _freeFunds(uint256 _amount) internal virtual;
  
      /**
       * @dev Internal function to harvest all rewards, redeploy any idle
       * funds and return an accurate accounting of all funds currently
       * held by the Strategy.
       *
       * This should do any needed harvesting, rewards selling, accrual,
       * redepositing etc. to get the most accurate view of current assets.
       *
       * NOTE: All applicable assets including loose assets should be
       * accounted for in this function.
       *
       * Care should be taken when relying on oracles or swap values rather
       * than actual amounts as all Strategy profit/loss accounting will
       * be done based on this returned value.
       *
       * This can still be called post a shutdown, a strategist can check
       * `TokenizedStrategy.isShutdown()` to decide if funds should be
       * redeployed or simply realize any profits/losses.
       *
       * @return _totalAssets A trusted and accurate account for the total
       * amount of 'asset' the strategy currently holds including idle funds.
       */
      function _harvestAndReport()
          internal
          virtual
          returns (uint256 _totalAssets);
  
      /*//////////////////////////////////////////////////////////////
                      OPTIONAL TO OVERRIDE BY STRATEGIST
      //////////////////////////////////////////////////////////////*/
  
      /**
       * @dev Optional function for strategist to override that can
       *  be called in between reports.
       *
       * If '_tend' is used tendTrigger() will also need to be overridden.
       *
       * This call can only be called by a permissioned role so may be
       * through protected relays.
       *
       * This can be used to harvest and compound rewards, deposit idle funds,
       * perform needed position maintenance or anything else that doesn't need
       * a full report for.
       *
       *   EX: A strategy that can not deposit funds without getting
       *       sandwiched can use the tend when a certain threshold
       *       of idle to totalAssets has been reached.
       *
       * The TokenizedStrategy contract will do all needed debt and idle updates
       * after this has finished and will have no effect on PPS of the strategy
       * till report() is called.
       *
       * @param _totalIdle The current amount of idle funds that are available to deploy.
       */
      function _tend(uint256 _totalIdle) internal virtual {}
  
      /**
       * @dev Optional trigger to override if tend() will be used by the strategy.
       * This must be implemented if the strategy hopes to invoke _tend().
       *
       * @return . Should return true if tend() should be called by keeper or false if not.
       */
      function _tendTrigger() internal view virtual returns (bool) {
          return false;
      }
  
      /**
       * @notice Returns if tend() should be called by a keeper.
       *
       * @return . Should return true if tend() should be called by keeper or false if not.
       * @return . Calldata for the tend call.
       */
      function tendTrigger() external view virtual returns (bool, bytes memory) {
          return (
              // Return the status of the tend trigger.
              _tendTrigger(),
              // And the needed calldata either way.
              abi.encodeWithSelector(ITokenizedStrategy.tend.selector)
          );
      }
  
      /**
       * @notice Gets the max amount of `asset` that an address can deposit.
       * @dev Defaults to an unlimited amount for any address. But can
       * be overridden by strategists.
       *
       * This function will be called before any deposit or mints to enforce
       * any limits desired by the strategist. This can be used for either a
       * traditional deposit limit or for implementing a whitelist etc.
       *
       *   EX:
       *      if(isAllowed[_owner]) return super.availableDepositLimit(_owner);
       *
       * This does not need to take into account any conversion rates
       * from shares to assets. But should know that any non max uint256
       * amounts may be converted to shares. So it is recommended to keep
       * custom amounts low enough as not to cause overflow when multiplied
       * by `totalSupply`.
       *
       * @param . The address that is depositing into the strategy.
       * @return . The available amount the `_owner` can deposit in terms of `asset`
       */
      function availableDepositLimit(
          address /*_owner*/
      ) public view virtual returns (uint256) {
          return type(uint256).max;
      }
  
      /**
       * @notice Gets the max amount of `asset` that can be withdrawn.
       * @dev Defaults to an unlimited amount for any address. But can
       * be overridden by strategists.
       *
       * This function will be called before any withdraw or redeem to enforce
       * any limits desired by the strategist. This can be used for illiquid
       * or sandwichable strategies. It should never be lower than `totalIdle`.
       *
       *   EX:
       *       return TokenIzedStrategy.totalIdle();
       *
       * This does not need to take into account the `_owner`'s share balance
       * or conversion rates from shares to assets.
       *
       * @param . The address that is withdrawing from the strategy.
       * @return . The available amount that can be withdrawn in terms of `asset`
       */
      function availableWithdrawLimit(
          address /*_owner*/
      ) public view virtual returns (uint256) {
          return type(uint256).max;
      }
  
      /**
       * @dev Optional function for a strategist to override that will
       * allow management to manually withdraw deployed funds from the
       * yield source if a strategy is shutdown.
       *
       * This should attempt to free `_amount`, noting that `_amount` may
       * be more than is currently deployed.
       *
       * NOTE: This will not realize any profits or losses. A separate
       * {report} will be needed in order to record any profit/loss. If
       * a report may need to be called after a shutdown it is important
       * to check if the strategy is shutdown during {_harvestAndReport}
       * so that it does not simply re-deploy all funds that had been freed.
       *
       * EX:
       *   if(freeAsset > 0 && !TokenizedStrategy.isShutdown()) {
       *       depositFunds...
       *    }
       *
       * @param _amount The amount of asset to attempt to free.
       */
      function _emergencyWithdraw(uint256 _amount) internal virtual {}
  
      /*//////////////////////////////////////////////////////////////
                          TokenizedStrategy HOOKS
      //////////////////////////////////////////////////////////////*/
  
      /**
       * @notice Should deploy up to '_amount' of 'asset' in yield source.
       * @dev Callback for the TokenizedStrategy to call during a {deposit}
       * or {mint} to tell the strategy it can deploy funds.
       *
       * Since this can only be called after a {deposit} or {mint}
       * delegateCall to the TokenizedStrategy msg.sender == address(this).
       *
       * Unless a whitelist is implemented this will be entirely permissionless
       * and thus can be sandwiched or otherwise manipulated.
       *
       * @param _amount The amount of 'asset' that the strategy should
       * attempt to deposit in the yield source.
       */
      function deployFunds(uint256 _amount) external virtual onlySelf {
          _deployFunds(_amount);
      }
  
      /**
       * @notice Will attempt to free the '_amount' of 'asset'.
       * @dev Callback for the TokenizedStrategy to call during a withdraw
       * or redeem to free the needed funds to service the withdraw.
       *
       * This can only be called after a 'withdraw' or 'redeem' delegateCall
       * to the TokenizedStrategy so msg.sender == address(this).
       *
       * @param _amount The amount of 'asset' that the strategy should attempt to free up.
       */
      function freeFunds(uint256 _amount) external virtual onlySelf {
          _freeFunds(_amount);
      }
  
      /**
       * @notice Returns the accurate amount of all funds currently
       * held by the Strategy.
       * @dev Callback for the TokenizedStrategy to call during a report to
       * get an accurate accounting of assets the strategy controls.
       *
       * This can only be called after a report() delegateCall to the
       * TokenizedStrategy so msg.sender == address(this).
       *
       * @return . A trusted and accurate account for the total amount
       * of 'asset' the strategy currently holds including idle funds.
       */
      function harvestAndReport() external virtual onlySelf returns (uint256) {
          return _harvestAndReport();
      }
  
      /**
       * @notice Will call the internal '_tend' when a keeper tends the strategy.
       * @dev Callback for the TokenizedStrategy to initiate a _tend call in the strategy.
       *
       * This can only be called after a tend() delegateCall to the TokenizedStrategy
       * so msg.sender == address(this).
       *
       * We name the function `tendThis` so that `tend` calls are forwarded to
       * the TokenizedStrategy so it can do the necessary accounting.
  
       * @param _totalIdle The amount of current idle funds that can be
       * deployed during the tend
       */
      function tendThis(uint256 _totalIdle) external virtual onlySelf {
          _tend(_totalIdle);
      }
  
      /**
       * @notice Will call the internal '_emergencyWithdraw' function.
       * @dev Callback for the TokenizedStrategy during an emergency withdraw.
       *
       * This can only be called after a emergencyWithdraw() delegateCall to
       * the TokenizedStrategy so msg.sender == address(this).
       *
       * We name the function `shutdownWithdraw` so that `emergencyWithdraw`
       * calls are forwarded to the TokenizedStrategy so it can do the necessary
       * accounting after the withdraw.
       *
       * @param _amount The amount of asset to attempt to free.
       */
      function shutdownWithdraw(uint256 _amount) external virtual onlySelf {
          _emergencyWithdraw(_amount);
      }
  
      function maxLTV() external view virtual returns (uint256);
  
      function collateral() external view virtual returns (address);
  
      /**
       * @dev Function used to delegate call the TokenizedStrategy with
       * certain `_calldata` and return any return values.
       *
       * This is used to setup the initial storage of the strategy, and
       * can be used by strategist to forward any other call to the
       * TokenizedStrategy implementation.
       *
       * @param _calldata The abi encoded calldata to use in delegatecall.
       * @return . The return value if the call was successful in bytes.
       */
      function _delegateCall(
          bytes memory _calldata
      ) internal returns (bytes memory) {
          // Delegate call the tokenized strategy with provided calldata.
          (bool success, bytes memory result) = tokenizedStrategyAddress
              .delegatecall(_calldata);
  
          // If the call reverted. Return the error.
          if (!success) {
              assembly {
                  let ptr := mload(0x40)
                  let size := returndatasize()
                  returndatacopy(ptr, 0, size)
                  revert(ptr, size)
              }
          }
  
          // Return the result.
          return result;
      }
  
      // execute a function on the TokenizedStrategy and return any value.
      fallback() external {
          // load our target address
          address _tokenizedStrategyAddress = tokenizedStrategyAddress;
          // Execute external function using delegatecall and return any value.
          assembly {
              // Copy function selector and any arguments.
              calldatacopy(0, 0, calldatasize())
              // Execute function delegatecall.
              let result := delegatecall(
                  gas(),
                  _tokenizedStrategyAddress,
                  0,
                  calldatasize(),
                  0,
                  0
              )
              // Get any return value
              returndatacopy(0, 0, returndatasize())
              // Return any return value or error back to the caller
              switch result
              case 0 {
                  revert(0, returndatasize())
              }
              default {
                  return(0, returndatasize())
              }
          }
      }
  }
  
  // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
  /**
   * @dev Collection of functions related to the address type
   */
  library Address {
      /**
       * @dev Returns true if `account` is a contract.
       *
       * [IMPORTANT]
       * ====
       * It is unsafe to assume that an address for which this function returns
       * false is an externally-owned account (EOA) and not a contract.
       *
       * Among others, `isContract` will return false for the following
       * types of addresses:
       *
       *  - an externally-owned account
       *  - a contract in construction
       *  - an address where a contract will be created
       *  - an address where a contract lived, but was destroyed
       *
       * Furthermore, `isContract` will also return true if the target contract within
       * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
       * which only has an effect at the end of a transaction.
       * ====
       *
       * [IMPORTANT]
       * ====
       * You shouldn't rely on `isContract` to protect against flash loan attacks!
       *
       * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
       * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
       * constructor.
       * ====
       */
      function isContract(address account) internal view returns (bool) {
          // This method relies on extcodesize/address.code.length, which returns 0
          // for contracts in construction, since the code is only stored at the end
          // of the constructor execution.
  
          return account.code.length > 0;
      }
  
      /**
       * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
       * `recipient`, forwarding all available gas and reverting on errors.
       *
       * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
       * of certain opcodes, possibly making contracts go over the 2300 gas limit
       * imposed by `transfer`, making them unable to receive funds via
       * `transfer`. {sendValue} removes this limitation.
       *
       * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
       *
       * IMPORTANT: because control is transferred to `recipient`, care must be
       * taken to not create reentrancy vulnerabilities. Consider using
       * {ReentrancyGuard} or the
       * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
       */
      function sendValue(address payable recipient, uint256 amount) internal {
          require(address(this).balance >= amount, "Address: insufficient balance");
  
          (bool success, ) = recipient.call{value: amount}("");
          require(success, "Address: unable to send value, recipient may have reverted");
      }
  
      /**
       * @dev Performs a Solidity function call using a low level `call`. A
       * plain `call` is an unsafe replacement for a function call: use this
       * function instead.
       *
       * If `target` reverts with a revert reason, it is bubbled up by this
       * function (like regular Solidity function calls).
       *
       * Returns the raw returned data. To convert to the expected return value,
       * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
       *
       * Requirements:
       *
       * - `target` must be a contract.
       * - calling `target` with `data` must not revert.
       *
       * _Available since v3.1._
       */
      function functionCall(address target, bytes memory data) internal returns (bytes memory) {
          return functionCallWithValue(target, data, 0, "Address: low-level call failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
       * `errorMessage` as a fallback revert reason when `target` reverts.
       *
       * _Available since v3.1._
       */
      function functionCall(
          address target,
          bytes memory data,
          string memory errorMessage
      ) internal returns (bytes memory) {
          return functionCallWithValue(target, data, 0, errorMessage);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but also transferring `value` wei to `target`.
       *
       * Requirements:
       *
       * - the calling contract must have an ETH balance of at least `value`.
       * - the called Solidity function must be `payable`.
       *
       * _Available since v3.1._
       */
      function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
          return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
       * with `errorMessage` as a fallback revert reason when `target` reverts.
       *
       * _Available since v3.1._
       */
      function functionCallWithValue(
          address target,
          bytes memory data,
          uint256 value,
          string memory errorMessage
      ) internal returns (bytes memory) {
          require(address(this).balance >= value, "Address: insufficient balance for call");
          (bool success, bytes memory returndata) = target.call{value: value}(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but performing a static call.
       *
       * _Available since v3.3._
       */
      function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
          return functionStaticCall(target, data, "Address: low-level static call failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
       * but performing a static call.
       *
       * _Available since v3.3._
       */
      function functionStaticCall(
          address target,
          bytes memory data,
          string memory errorMessage
      ) internal view returns (bytes memory) {
          (bool success, bytes memory returndata) = target.staticcall(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but performing a delegate call.
       *
       * _Available since v3.4._
       */
      function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
          return functionDelegateCall(target, data, "Address: low-level delegate call failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
       * but performing a delegate call.
       *
       * _Available since v3.4._
       */
      function functionDelegateCall(
          address target,
          bytes memory data,
          string memory errorMessage
      ) internal returns (bytes memory) {
          (bool success, bytes memory returndata) = target.delegatecall(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
       * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
       *
       * _Available since v4.8._
       */
      function verifyCallResultFromTarget(
          address target,
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal view returns (bytes memory) {
          if (success) {
              if (returndata.length == 0) {
                  // only check isContract if the call was successful and the return data is empty
                  // otherwise we already know that it was a contract
                  require(isContract(target), "Address: call to non-contract");
              }
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      /**
       * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
       * revert reason or using the provided one.
       *
       * _Available since v4.3._
       */
      function verifyCallResult(
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal pure returns (bytes memory) {
          if (success) {
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      function _revert(bytes memory returndata, string memory errorMessage) private pure {
          // Look for revert reason and bubble it up if present
          if (returndata.length > 0) {
              // The easiest way to bubble the revert reason is using memory via assembly
              /// @solidity memory-safe-assembly
              assembly {
                  let returndata_size := mload(returndata)
                  revert(add(32, returndata), returndata_size)
              }
          } else {
              revert(errorMessage);
          }
      }
  }
  
  library SafeERC20 {
      using Address for address;
  
      /**
       * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeTransfer(IERC20 token, address to, uint256 value) internal {
          _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
      }
  
      /**
       * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
       * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
       */
      function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
          _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
      }
  
      /**
       * @dev Deprecated. This function has issues similar to the ones found in
       * {IERC20-approve}, and its usage is discouraged.
       *
       * Whenever possible, use {safeIncreaseAllowance} and
       * {safeDecreaseAllowance} instead.
       */
      function safeApprove(IERC20 token, address spender, uint256 value) internal {
          // safeApprove should only be called when setting an initial allowance,
          // or when resetting it to zero. To increase and decrease it, use
          // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
          require(
              (value == 0) || (token.allowance(address(this), spender) == 0),
              "SafeERC20: approve from non-zero to non-zero allowance"
          );
          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
      }
  
      /**
       * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
          uint256 oldAllowance = token.allowance(address(this), spender);
          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
      }
  
      /**
       * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
          unchecked {
              uint256 oldAllowance = token.allowance(address(this), spender);
              require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
          }
      }
  
      /**
       * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
       * to be set to zero before setting it to a non-zero value, such as USDT.
       */
      function forceApprove(IERC20 token, address spender, uint256 value) internal {
          bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
  
          if (!_callOptionalReturnBool(token, approvalCall)) {
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
              _callOptionalReturn(token, approvalCall);
          }
      }
  
      /**
       * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
       * Revert on invalid signature.
       */
      function safePermit(
          IERC20Permit token,
          address owner,
          address spender,
          uint256 value,
          uint256 deadline,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) internal {
          uint256 nonceBefore = token.nonces(owner);
          token.permit(owner, spender, value, deadline, v, r, s);
          uint256 nonceAfter = token.nonces(owner);
          require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
      }
  
      /**
       * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
       * on the return value: the return value is optional (but if data is returned, it must not be false).
       * @param token The token targeted by the call.
       * @param data The call data (encoded using abi.encode or one of its variants).
       */
      function _callOptionalReturn(IERC20 token, bytes memory data) private {
          // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
          // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
          // the target address contains contract code and also asserts for success in the low-level call.
  
          bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
          require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
      }
  
      /**
       * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
       * on the return value: the return value is optional (but if data is returned, it must not be false).
       * @param token The token targeted by the call.
       * @param data The call data (encoded using abi.encode or one of its variants).
       *
       * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
       */
      function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
          // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
          // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
          // and not revert is the subcall reverts.
  
          (bool success, bytes memory returndata) = address(token).call(data);
          return
              success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
      }
  }
  
  library Math {
      enum Rounding {
          Down, // Toward negative infinity
          Up, // Toward infinity
          Zero // Toward zero
      }
  
      /**
       * @dev Returns the largest of two numbers.
       */
      function max(uint256 a, uint256 b) internal pure returns (uint256) {
          return a > b ? a : b;
      }
  
      /**
       * @dev Returns the smallest of two numbers.
       */
      function min(uint256 a, uint256 b) internal pure returns (uint256) {
          return a < b ? a : b;
      }
  
      /**
       * @dev Returns the average of two numbers. The result is rounded towards
       * zero.
       */
      function average(uint256 a, uint256 b) internal pure returns (uint256) {
          // (a + b) / 2 can overflow.
          return (a & b) + (a ^ b) / 2;
      }
  
      /**
       * @dev Returns the ceiling of the division of two numbers.
       *
       * This differs from standard division with `/` in that it rounds up instead
       * of rounding down.
       */
      function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
          // (a + b - 1) / b can overflow on addition, so we distribute.
          return a == 0 ? 0 : (a - 1) / b + 1;
      }
  
      /**
       * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
       * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
       * with further edits by Uniswap Labs also under MIT license.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
          unchecked {
              // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
              // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
              // variables such that product = prod1 * 2^256 + prod0.
              uint256 prod0; // Least significant 256 bits of the product
              uint256 prod1; // Most significant 256 bits of the product
              assembly {
                  let mm := mulmod(x, y, not(0))
                  prod0 := mul(x, y)
                  prod1 := sub(sub(mm, prod0), lt(mm, prod0))
              }
  
              // Handle non-overflow cases, 256 by 256 division.
              if (prod1 == 0) {
                  // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                  // The surrounding unchecked block does not change this fact.
                  // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                  return prod0 / denominator;
              }
  
              // Make sure the result is less than 2^256. Also prevents denominator == 0.
              require(denominator > prod1, "Math: mulDiv overflow");
  
              ///////////////////////////////////////////////
              // 512 by 256 division.
              ///////////////////////////////////////////////
  
              // Make division exact by subtracting the remainder from [prod1 prod0].
              uint256 remainder;
              assembly {
                  // Compute remainder using mulmod.
                  remainder := mulmod(x, y, denominator)
  
                  // Subtract 256 bit number from 512 bit number.
                  prod1 := sub(prod1, gt(remainder, prod0))
                  prod0 := sub(prod0, remainder)
              }
  
              // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
              // See https://cs.stackexchange.com/q/138556/92363.
  
              // Does not overflow because the denominator cannot be zero at this stage in the function.
              uint256 twos = denominator & (~denominator + 1);
              assembly {
                  // Divide denominator by twos.
                  denominator := div(denominator, twos)
  
                  // Divide [prod1 prod0] by twos.
                  prod0 := div(prod0, twos)
  
                  // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                  twos := add(div(sub(0, twos), twos), 1)
              }
  
              // Shift in bits from prod1 into prod0.
              prod0 |= prod1 * twos;
  
              // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
              // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
              // four bits. That is, denominator * inv = 1 mod 2^4.
              uint256 inverse = (3 * denominator) ^ 2;
  
              // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
              // in modular arithmetic, doubling the correct bits in each step.
              inverse *= 2 - denominator * inverse; // inverse mod 2^8
              inverse *= 2 - denominator * inverse; // inverse mod 2^16
              inverse *= 2 - denominator * inverse; // inverse mod 2^32
              inverse *= 2 - denominator * inverse; // inverse mod 2^64
              inverse *= 2 - denominator * inverse; // inverse mod 2^128
              inverse *= 2 - denominator * inverse; // inverse mod 2^256
  
              // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
              // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
              // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
              // is no longer required.
              result = prod0 * inverse;
              return result;
          }
      }
  
      /**
       * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
          uint256 result = mulDiv(x, y, denominator);
          if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
              result += 1;
          }
          return result;
      }
  
      /**
       * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
       *
       * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
       */
      function sqrt(uint256 a) internal pure returns (uint256) {
          if (a == 0) {
              return 0;
          }
  
          // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
          //
          // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
          // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
          //
          // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
          // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
          // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
          //
          // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
          uint256 result = 1 << (log2(a) >> 1);
  
          // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
          // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
          // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
          // into the expected uint128 result.
          unchecked {
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              return min(result, a / result);
          }
      }
  
      /**
       * @notice Calculates sqrt(a), following the selected rounding direction.
       */
      function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = sqrt(a);
              return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 2, rounded down, of a positive value.
       * Returns 0 if given 0.
       */
      function log2(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 128;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 64;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 32;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 16;
              }
              if (value >> 8 > 0) {
                  value >>= 8;
                  result += 8;
              }
              if (value >> 4 > 0) {
                  value >>= 4;
                  result += 4;
              }
              if (value >> 2 > 0) {
                  value >>= 2;
                  result += 2;
              }
              if (value >> 1 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log2(value);
              return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 10, rounded down, of a positive value.
       * Returns 0 if given 0.
       */
      function log10(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >= 10 ** 64) {
                  value /= 10 ** 64;
                  result += 64;
              }
              if (value >= 10 ** 32) {
                  value /= 10 ** 32;
                  result += 32;
              }
              if (value >= 10 ** 16) {
                  value /= 10 ** 16;
                  result += 16;
              }
              if (value >= 10 ** 8) {
                  value /= 10 ** 8;
                  result += 8;
              }
              if (value >= 10 ** 4) {
                  value /= 10 ** 4;
                  result += 4;
              }
              if (value >= 10 ** 2) {
                  value /= 10 ** 2;
                  result += 2;
              }
              if (value >= 10 ** 1) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log10(value);
              return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 256, rounded down, of a positive value.
       * Returns 0 if given 0.
       *
       * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
       */
      function log256(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 16;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 8;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 4;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 2;
              }
              if (value >> 8 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log256(value);
              return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
          }
      }
  }
  
  struct VaultAccount {
      uint128 amount; // Total amount, analogous to market cap
      uint128 shares; // Total shares, analogous to shares outstanding
  }
  
  interface ISturdyPair {
      struct CurrentRateInfo {
          uint32 lastBlock;
          uint32 feeToProtocolRate; // Fee amount 1e5 precision
          uint64 lastTimestamp;
          uint64 ratePerSec;
          uint64 fullUtilizationRate;
      }
  
      function CIRCUIT_BREAKER_ADDRESS() external view returns (address);
  
      function COMPTROLLER_ADDRESS() external view returns (address);
  
      function DEPLOYER_ADDRESS() external view returns (address);
  
      function FRAXLEND_WHITELIST_ADDRESS() external view returns (address);
  
      function timelockAddress() external view returns (address);
  
      function addCollateral(uint256 _collateralAmount, address _borrower) external;
      
      function addInterest(
          bool _returnAccounting
      )
          external
          returns (
              uint256 _interestEarned,
              uint256 _feesAmount,
              uint256 _feesShare,
              CurrentRateInfo memory _currentRateInfo,
              VaultAccount memory _totalAsset,
              VaultAccount memory _totalBorrow
          );
  
      function allowance(address owner, address spender) external view returns (uint256);
  
      function approve(address spender, uint256 amount) external returns (bool);
  
      function approvedBorrowers(address) external view returns (bool);
  
      function approvedLenders(address) external view returns (bool);
  
      function approveBorrowDelegation(address _delegatee, uint256 _amount) external;
  
      function asset() external view returns (address);
  
      function balanceOf(address account) external view returns (uint256);
  
      function borrowAsset(
          uint256 _borrowAmount,
          uint256 _collateralAmount,
          address _receiver
      ) external returns (uint256 _shares);
  
      function borrowAssetOnBehalfOf(
          uint256 _borrowAmount,
          address _onBehalfOf
      ) external returns (uint256 _shares);
  
      function borrowerWhitelistActive() external view returns (bool);
  
      function changeFee(uint32 _newFee) external;
  
      function cleanLiquidationFee() external view returns (uint256);
  
      function collateralContract() external view returns (address);
  
      function currentRateInfo()
          external
          view
          returns (
              uint32 lastBlock,
              uint32 feeToProtocolRate,
              uint64 lastTimestamp,
              uint64 ratePerSec,
              uint64 fullUtilizationRate
          );
  
      function decimals() external view returns (uint8);
  
      function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool);
  
      function deposit(uint256 _amount, address _receiver) external returns (uint256 _sharesReceived);
  
      function dirtyLiquidationFee() external view returns (uint256);
  
      function exchangeRateInfo() external view returns (address oracle, uint32 maxOracleDeviation, uint184 lastTimestamp, uint256 lowExchangeRate, uint256 highExchangeRate);
  
      function getConstants()
          external
          pure
          returns (
              uint256 _LTV_PRECISION,
              uint256 _LIQ_PRECISION,
              uint256 _UTIL_PREC,
              uint256 _FEE_PRECISION,
              uint256 _EXCHANGE_PRECISION,
              uint256 _DEVIATION_PRECISION,
              uint256 _RATE_PRECISION,
              uint256 _MAX_PROTOCOL_FEE
          );
  
      function getImmutableAddressBool()
          external
          view
          returns (
              address _assetContract,
              address _collateralContract,
              address _oracleMultiply,
              address _oracleDivide,
              address _rateContract,
              address _DEPLOYER_CONTRACT,
              address _COMPTROLLER_ADDRESS,
              address _FRAXLEND_WHITELIST,
              bool _borrowerWhitelistActive,
              bool _lenderWhitelistActive
          );
  
      function getImmutableUint256()
          external
          view
          returns (
              uint256 _oracleNormalization,
              uint256 _maxLTV,
              uint256 _cleanLiquidationFee,
              uint256 _maturityDate,
              uint256 _penaltyRate
          );
  
      function getPairAccounting()
          external
          view
          returns (
              uint128 _totalAssetAmount,
              uint128 _totalAssetShares,
              uint128 _totalBorrowAmount,
              uint128 _totalBorrowShares,
              uint256 _totalCollateral
          );
  
      function getUserSnapshot(
          address _address
      ) external view returns (uint256 _userAssetShares, uint256 _userBorrowShares, uint256 _userCollateralBalance);
  
      function increaseAllowance(address spender, uint256 addedValue) external returns (bool);
  
      function lenderWhitelistActive() external view returns (bool);
  
      function leveragedPosition(
          address _swapperAddress,
          uint256 _borrowAmount,
          uint256 _initialCollateralAmount,
          uint256 _amountCollateralOutMin,
          address[] memory _path
      ) external returns (uint256 _totalCollateralBalance);
  
      function liquidate(
          uint128 _sharesToLiquidate,
          uint256 _deadline,
          address _borrower
      ) external returns (uint256 _collateralForLiquidator);
  
      function maturityDate() external view returns (uint256);
  
      function maxLTV() external view returns (uint256);
  
      function maxOracleDelay() external view returns (uint256);
  
      function name() external view returns (string memory);
  
      function oracleDivide() external view returns (address);
  
      function oracleMultiply() external view returns (address);
  
      function oracleNormalization() external view returns (uint256);
  
      function owner() external view returns (address);
  
      function pause() external;
  
      function paused() external view returns (bool);
  
      function penaltyRate() external view returns (uint256);
  
      function rateContract() external view returns (address);
  
      function redeem(uint256 _shares, address _receiver, address _owner) external returns (uint256 _amountToReturn);
  
      function removeCollateral(uint256 _collateralAmount, address _receiver) external;
  
      function removeCollateralFrom(
          uint256 _collateralAmount,
          address _receiver,
          address _borrower
      ) external;
  
      function setWhitelistedDelegators(address _delegator, bool _enabled) external;
  
      function renounceOwnership() external;
  
      function repayAsset(uint256 _shares, address _borrower) external returns (uint256 _amountToRepay);
  
      function repayAssetWithCollateral(
          address _swapperAddress,
          uint256 _collateralToSwap,
          uint256 _amountAssetOutMin,
          address[] memory _path
      ) external returns (uint256 _amountAssetOut);
  
      function setApprovedBorrowers(address[] memory _borrowers, bool _approval) external;
  
      function setApprovedLenders(address[] memory _lenders, bool _approval) external;
  
      function setMaxOracleDelay(uint256 _newDelay) external;
  
      function setSwapper(address _swapper, bool _approval) external;
  
      function setTimelock(address _newAddress) external;
  
      function swappers(address) external view returns (bool);
  
      function symbol() external view returns (string memory);
  
      function toAssetAmount(
          uint256 _shares,
          bool _roundUp,
          bool _previewInterest
      ) external view returns (uint256);
  
      function toAssetShares(
          uint256 _amount,
          bool _roundUp,
          bool _previewInterest
      ) external view returns (uint256);
  
      function toBorrowAmount(
          uint256 _shares,
          bool _roundUp,
          bool _previewInterest
      ) external view returns (uint256 _amount);
  
      function toBorrowShares(
          uint256 _amount,
          bool _roundUp,
          bool _previewInterest
      ) external view returns (uint256 _shares);
  
      function totalAsset() external view returns (uint128 amount, uint128 shares);
  
      function totalBorrow() external view returns (uint128 amount, uint128 shares);
  
      function totalCollateral() external view returns (uint256);
  
      function totalSupply() external view returns (uint256);
  
      function transfer(address to, uint256 amount) external returns (bool);
  
      function transferFrom(address from, address to, uint256 amount) external returns (bool);
  
      function transferOwnership(address newOwner) external;
  
      function unpause() external;
  
      function updateExchangeRate()
          external
          returns (bool _isBorrowAllowed, uint256 _lowExchangeRate, uint256 _highExchangeRate);
  
      function userBorrowShares(address) external view returns (uint256);
  
      function userCollateralBalance(address) external view returns (uint256);
  
      function version() external pure returns (uint256 _major, uint256 _minor, uint256 _patch);
  
      function withdrawFees(uint128 _shares, address _recipient) external returns (uint256 _amountToTransfer);
  
      function isInterestPaused() external view returns (bool);
  }
  
  contract SturdySiloStrategy is BaseStrategy {
      using SafeERC20 for ERC20;
  
      ISturdyPair public immutable pair;
  
      // Amount of deposits we need before depositing
      uint256 public immutable depositThreshold;
      // Bool if we have met the depositThreshold
      bool public thresholdMet;
  
      // Timestamp of when withdraws will be enabled
      uint256 public timeToUnlock;
      // If the timeToUnlock is still able to be set. (false == can still be set.)
      bool public freezeTimeToUnlock;
  
      constructor(
          address _asset,
          address _pair,
          string memory _name,
          uint256 _depositThreshold,
          uint256 _timeToUnlock
      ) BaseStrategy(_asset, _name) {
          // Set pair address
          pair = ISturdyPair(_pair);
          // Set depositThreshold value
          depositThreshold = _depositThreshold;
          // Set initial time to unlock
          timeToUnlock = _timeToUnlock;
          // Approve the pair for FRAX
          ERC20(_asset).safeApprove(address(pair), type(uint256).max);
      }
  
      /*//////////////////////////////////////////////////////////////
                  NEEDED TO BE OVERRIDEN BY STRATEGIST
      //////////////////////////////////////////////////////////////*/
  
      /**
       * @dev Should deploy up to '_amount' of 'asset' in the yield source.
       *
       * This function is called at the end of a {deposit} or {mint}
       * call. Meaning that unless a whitelist is implemented it will
       * be entirely permsionless and thus can be sandwhiched or otherwise
       * manipulated.
       *
       * @param _amount The amount of 'asset' that the strategy should attemppt
       * to deposit in the yield source.
       */
      function _deployFunds(uint256 _amount) internal override {
          // We don't deposit until the threshold is met.
          if (thresholdMet) {
              pair.deposit(_amount, address(this));
  
              // Amount will include all idle funds if not deposited yet.
          } else if (_amount > depositThreshold) {
              // Set the bool for easy checks in the future.
              thresholdMet = true;
              pair.deposit(_amount, address(this));
          }
      }
  
      /**
       * @dev Will attempt to free the '_amount' of 'asset'.
       *
       * The amount of 'asset' that is already loose has already
       * been accounted for.
       *
       * This function is called during {withdraw} and {redeem} calls.
       * Meaning that unless a whitelist is implemented it will be
       * entirely permsionless and thus can be sandwhiched or otherwise
       * manipulated.
       *
       * Should not rely on asset.balanceOf(address(this)) calls other than
       * for diff accounting puroposes.
       *
       * Any difference between `_amount` and what is actually freed will be
       * counted as a loss and passed on to the withdrawer. This means
       * care should be taken in times of illiquidity. It may be better to revert
       * if withdraws are simply illiquid so not to realize incorrect losses.
       *
       * @param _amount, The amount of 'asset' to be freed.
       */
      function _freeFunds(uint256 _amount) internal override {
          // Only proccess withdraws if we have unlocked the stratey
          if (block.timestamp >= timeToUnlock) {
              // Accrue interest for conversion.
              pair.addInterest(false);
              pair.redeem(
                  pair.toAssetShares(_amount, false, false),
                  address(this),
                  address(this)
              );
          } else {
              // This should never happen but we check just in case and
              // revert so we don't record an incorrect loss.
              require(false, "Locked!");
          }
      }
  
      /**
       * @dev Internal function to harvest all rewards, redeploy any idle
       * funds and return an accurate accounting of all funds currently
       * held by the Strategy.
       *
       * This should do any needed harvesting, rewards selling, accrual,
       * redepositing etc. to get the most accurate view of current assets.
       *
       * NOTE: All applicable assets including loose assets should be
       * accounted for in this function.
       *
       * Care should be taken when relying on oracles or swap values rather
       * than actual amounts as all Strategy profit/loss accounting will
       * be done based on this returned value.
       *
       * This can still be called post a shutdown, a strategist can check
       * `TokenizedStrategy.isShutdown()` to decide if funds should be
       * redeployed or simply realize any profits/losses.
       *
       * @return _totalAssets A trusted and accurate account for the total
       * amount of 'asset' the strategy currently holds including idle funds.
       */
      function _harvestAndReport()
          internal
          override
          returns (uint256 _totalAssets)
      {
          // Acccrue interest
          pair.addInterest(false);
  
          _totalAssets =
              // Return total balance including idle.
              asset.balanceOf(address(this)) +
              pair.toAssetAmount(pair.balanceOf(address(this)), false, false);
      }
  
      /*//////////////////////////////////////////////////////////////
                      OPTIONAL TO OVERRIDE BY STRATEGIST
      //////////////////////////////////////////////////////////////*/
  
      /**
       * @notice Gets the max amount of `asset` that can be withdrawn.
       * @dev Defaults to an unlimited amount for any address. But can
       * be overriden by strategists.
       *
       * This function will be called before any withdraw or redeem to enforce
       * any limits desired by the strategist. This can be used for illiquid
       * or sandwhichable strategies. It should never be lower than `totalIdle`.
       *
       *   EX:
       *       return TokenIzedStrategy.totalIdle();
       *
       * This does not need to take into account the `_owner`'s share balance
       * or conversion rates from shares to assets.
       *
       * @param . The address that is withdrawing from the strategy.
       * @return . The avialable amount that can be withdrawn in terms of `asset`
       */
      function availableWithdrawLimit(
          address _owner
      ) public view override returns (uint256) {
          // If we have passed the unlock time we have no limit.
          if (block.timestamp >= timeToUnlock) {
              return
                  TokenizedStrategy.totalIdle() +
                  asset.balanceOf(address(pair));
          } else {
              // Otherwise just the amount of idle can be withdrawn.
              return TokenizedStrategy.totalIdle();
          }
      }
  
      /**
       * @dev Optional function for a strategist to override that will
       * allow management to manually withdraw deployed funds from the
       * yield source if a strategy is shutdown.
       *
       * This should attempt to free `_amount`, noting that `_amount` may
       * be more than is currently deployed.
       *
       * NOTE: This will not realize any profits or losses. A seperate
       * {report} will be needed in order to record any profit/loss. If
       * a report may need to be called after a shutdown it is important
       * to check if the strategy is shutdown during {_harvestAndReport}
       * so that it does not simply re-deploy all funds that had been freed.
       *
       * EX:
       *   if(freeAsset > 0 && !TokenizedStrategy.isShutdown()) {
       *       depositFunds...
       *    }
       *
       * @param _amount The amount of asset to attempt to free.
       */
      function _emergencyWithdraw(uint256 _amount) internal override {
          pair.addInterest(false);
          // Round up and check against actual balance
          uint256 shares = pair.toAssetShares(_amount, true, false);
  
          shares = Math.min(shares, pair.balanceOf(address(this)));
          pair.redeem(shares, address(this), address(this));
      }
  
      // Management can update the unlock time unless it has been frozen.
      function setTimeToUnlock(uint256 _newTime) external onlyManagement {
          require(!freezeTimeToUnlock, "lock frozen");
          timeToUnlock = _newTime;
      }
  
      // One way switch to freeze the unlock time.
      function freezeUnlock() external onlyManagement {
          freezeTimeToUnlock = true;
      }
  
      function maxLTV() external view override returns (uint256) {
          return pair.maxLTV();
      }
  
      function collateral() external view override returns (address) {
          return pair.collateralContract();
      }
  }