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contracts...TestGasUse.sol

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;

contract TestGasUsage {
    
    function displayGasUage() public view returns(uint) {
        uint256 startGas = gasleft();
        
        //int number = 5;
        uint256 usedGas = startGas - gasleft();
        return usedGas;
    }
}