creation_sourcecode: // SPDX-License-Identifier: MIT
  
  pragma solidity ^0.8.19;
  
  interface IERC20 {
  
      function totalSupply() external view returns (uint256);
  
      function balanceOf(address account) external view returns (uint256);
  
      function transfer(address recipient, uint256 amount) external returns (bool);
  
      function allowance(address owner, address spender) external view returns (uint256);
  
      function approve(address spender, uint256 amount) external returns (bool);
  
      function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
  
      event Transfer(address indexed from, address indexed to, uint256 value);
  
      event Approval(address indexed owner, address indexed spender, uint256 value);
  }
  
  interface IERC20Metadata is IERC20 {
     
      function name() external view returns (string memory);
  
      function symbol() external view returns (string memory);
  
      function decimals() external view returns (uint8);
  }
  
  abstract contract Context {
      function _msgSender() internal view virtual returns (address) {
          return msg.sender;
      }
  
      function _msgData() internal view virtual returns (bytes calldata) {
          this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
          return msg.data;
      }
  }
  
  abstract contract Ownable is Context {
      address private _owner;
  
      event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  
      /**
       * @dev Initializes the contract setting the deployer as the initial owner.
       */
      constructor () {
          address msgSender = _msgSender();
          _owner = msg.sender;
          emit OwnershipTransferred(address(0), msgSender);
      }
  
      /**
       * @dev Returns the address of the current owner.
       */
      function owner() public view virtual returns (address) {
          return _owner;
      }
  
      modifier onlyOwner() {
          require(owner() == _msgSender(), "Ownable: caller is not the owner");
          _;
      }
  
      function renounceOwnership() public virtual onlyOwner {
          emit OwnershipTransferred(_owner, address(0));
          _owner = address(0);
      }
  
      function transferOwnership(address newOwner) public virtual onlyOwner {
          require(newOwner != address(0), "Ownable: new owner is the zero address");
          emit OwnershipTransferred(_owner, newOwner);
          _owner = newOwner;
      }
  }
  
  
  
  contract Rollblock is Context, IERC20, IERC20Metadata, Ownable{
      mapping (address => uint256) private _balances;
  
      mapping (address => mapping (address => uint256)) private _allowances;
  
      uint256 private _totalSupply;
  
      string private _name;
      string private _symbol;
  
      constructor () {
          _name = "Rollblock"; 
          _symbol = "RBLK";
          _totalSupply;
          _mint(owner(), 1_000_000_000 ether );
      }
      
      function name() public view virtual override returns (string memory) {
          return _name;
      }
  
      function symbol() public view virtual override returns (string memory) {
          return _symbol;
      }
  
      function decimals() public view virtual override returns (uint8) {
          return 18;
      }
  
      function totalSupply() public view virtual override returns (uint256) {
          return _totalSupply;
      }
  
      function balanceOf(address account) public view virtual override returns (uint256) {
          return _balances[account];
      }
  
      function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
          _transfer(_msgSender(), recipient, amount);
          return true;
      }
  
      function allowance(address owner, address spender) public view virtual override returns (uint256) {
          return _allowances[owner][spender];
      }
  
      function approve(address spender, uint256 amount) public virtual override returns (bool) {
          _approve(_msgSender(), spender, amount);
          return true;
      }
  
      function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
          _transfer(sender, recipient, amount);
  
          uint256 currentAllowance = _allowances[sender][_msgSender()];
          require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
          _approve(sender, _msgSender(), currentAllowance - amount);
  
          return true;
      }
  
      function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
          _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
          return true;
      }
  
      function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
          uint256 currentAllowance = _allowances[_msgSender()][spender];
          require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
          _approve(_msgSender(), spender, currentAllowance - subtractedValue);
  
          return true;
      }
  
      function _transfer(address sender, address recipient, uint256 amount) internal virtual {
          require(sender != address(0), "ERC2020: transfer from the zero address");
          require(recipient != address(0), "ERC20: transfer to the zero address");
  
          _beforeTokenTransfer(sender, recipient, amount);
  
          uint256 senderBalance = _balances[sender];
          require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
          _balances[sender] = senderBalance - amount;
          _balances[recipient] += amount;
  
          emit Transfer(sender, recipient, amount);
      }
  
      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;
          _balances[account] += amount;
          emit Transfer(address(0), account, amount);
      }
  
      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");
          _balances[account] = accountBalance - amount;
          _totalSupply -= amount;
  
          emit Transfer(account, address(0), amount);
      }
  
      function burn(uint256 amount) public onlyOwner {
          _burn(msg.sender, amount);
      }
      
      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);
      }
  
      function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
  }