contract Operator is Ownable {
    mapping(uint256=>address) private _operators;
    /**
     * @dev modifier, Only indexed operator can be granted exclusive access to specific functions. 
     *
     */
    modifier onlyOperator(uint256 index) {
        require(_operators[index] == msg.sender,"Operator: caller is not the eligible Operator");
        _;
    }
    /**
     * @dev modify indexed operator by owner. 
     *
     */
    function setOperator(uint256 index,address addAddress)public onlyOwner{
        _operators[index] = addAddress;
    }
    function getOperator(uint256 index)public view returns (address) {
        return _operators[index];
    }
}
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * each operator can be granted exclusive access to specific functions.
 *
 */
function setOperator(uint256 index,address addAddress)public onlyOwner{
    _operators[index] = addAddress;
}

/**
 * @dev modify indexed operator by owner. 
 *
 */