creation_sourcecode: // SPDX-License-Identifier: MIT
  pragma solidity ^0.8.0;
  
  interface IERC20 {
      event Transfer(address indexed from, address indexed to, uint256 value);
      event Approval(address indexed owner, address indexed spender, uint256 value);
  
      function name() external view returns (string memory);
      function symbol() external view returns (string memory);
      function decimals() external view returns (uint8);
      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);
      function increaseAllowance(address spender, uint256 addedValue) external returns (bool);
      function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool);
  }
  
  contract USDT is IERC20 {
      mapping (address => uint256) private _balances;
      mapping (address => mapping (address => uint256)) private _allowances;
  
      uint256 private _totalSupply;
  
      string private _name;
      string private _symbol;
      uint8 private _decimals;
  
      constructor() {
          _name = "Tether USD";
          _symbol = "USDT";
          _decimals = 18;
          _totalSupply = 10000000 * 10 ** uint256(_decimals);
          _balances[msg.sender] = _totalSupply;
  
          emit Transfer(address(0), msg.sender, _totalSupply);
      }
  
      function name() public view override returns (string memory) {
          return _name;
      }
  
      function symbol() public view override returns (string memory) {
          return _symbol;
      }
  
      function decimals() public view override returns (uint8) {
          return _decimals;
      }
  
      function totalSupply() public view override returns (uint256) {
          return _totalSupply;
      }
  
      function balanceOf(address account) public view override returns (uint256) {
          return _balances[account];
      }
  
      function transfer(address recipient, uint256 amount) public override returns (bool) {
          _transfer(msg.sender, recipient, amount);
          return true;
      }
  
      function allowance(address owner, address spender) public view override returns (uint256) {
          return _allowances[owner][spender];
      }
  
      function approve(address spender, uint256 amount) public override returns (bool) {
          _approve(msg.sender, spender, amount);
          return true;
      }
  
      function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
          _transfer(sender, recipient, amount);
          _approve(sender, msg.sender, _allowances[sender][msg.sender] - amount);
          return true;
      }
  
      function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
          _approve(msg.sender, spender, _allowances[msg.sender][spender] + addedValue);
          return true;
      }
  
      function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
          _approve(msg.sender, spender, _allowances[msg.sender][spender] - subtractedValue);
          return true;
      }
  
      function _transfer(address sender, address recipient, uint256 amount) internal {
          require(sender != address(0), "ERC20: transfer from the zero address");
          require(recipient != address(0), "ERC20: transfer to the zero address");
  
          _balances[sender] -= amount;
          _balances[recipient] += amount;
  
          emit Transfer(sender, recipient, amount);
      }
  
      function _approve(address owner, address spender, uint256 amount) internal {
          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);
      }
  }