    function mint(address to, uint256 amount) public virtual {
        if (!hasRole(MASTER_MINTER, _msgSender()) && !hasRole(MINTER_ROLE, _msgSender()))
            revert NotMinter(_msgSender());
@>      if (amount <= 0) revert InvalidAmount(amount);
    function setTxFeeRate(uint256 newTxFeeRate) public virtual {
@>      if (newTxFeeRate > FEE_RATIO || newTxFeeRate < 0) revert InvalidFeeRate(FEE_RATIO, newTxFeeRate);
        _txfeeRate = newTxFeeRate;
        emit TxFeeRateUpdated(newTxFeeRate);
    }
    function setGaslessBasefee(uint256 newGaslessBasefee) public virtual {
@>      if (newGaslessBasefee < 0) revert NegativeBasefee();
        _gaslessBasefee = newGaslessBasefee;
        emit GaslessBasefeeUpdated(newGaslessBasefee);
    }
