Demo solidity contract to demo custom errors

DemoCustomError.sol

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.7;

contract DemoCustomError {

    error Unauthorized();
    error myCustomError(string message);

    address public owner = address(0x0);

    function checkAuthorisation() public view {
        if(msg.sender != owner) {
            revert Unauthorized();
        }
    }

    function testCustomErrorMessage(string calldata message) public pure {
        revert myCustomError(message);
    }

}