operatorAuth.sol

    /**
     * @dev See `IERC777.authorizeOperator`.
     */
    function authorizeOperator(address operator) external {
        require(msg.sender != operator, "ERC777: authorizing self as operator");

        if (_defaultOperators[operator]) {
            delete _revokedDefaultOperators[msg.sender][operator];
        } else {
            _operators[msg.sender][operator] = true;
        }

        emit AuthorizedOperator(operator, msg.sender);
    }

    /**
     * @dev See `IERC777.revokeOperator`.
     */
    function revokeOperator(address operator) external {
        require(operator != msg.sender, "ERC777: revoking self as operator");

        if (_defaultOperators[operator]) {
            _revokedDefaultOperators[msg.sender][operator] = true;
        } else {
            delete _operators[msg.sender][operator];
        }

        emit RevokedOperator(operator, msg.sender);
    }