function oraclize_query(string memory _datasource, string memory _arg1, string memory _arg2) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; 
        }
        return oraclize.query2.value(price)(0, _datasource, _arg1, _arg2);
    }