{
    "_yql_row_spec" = {
        "Type" = [
            "StructType";
            [
                [
                    "finterval1";
                    [
                        "OptionalType";
                        [
                            "DataType";
                            "String"
                        ]
                    ]
                ];
                [
                    "finterval2";
                    [
                        "OptionalType";
                        [
                            "DataType";
                            "String"
                        ]
                    ]
                ];
                [
                    "finterval3";
                    [
                        "OptionalType";
                        [
                            "DataType";
                            "String"
                        ]
                    ]
                ];
                [
                    "finterval4";
                    [
                        "OptionalType";
                        [
                            "DataType";
                            "String"
                        ]
                    ]
                ];
            ]
        ]
    }
}