def METHOD_NAME():
    numbers = ak.contents.IndexedArray(
        ak.index.Index64([0, 2, 3]),
        ak.contents.NumpyArray(np.arange(10, dtype=np.int64)),
        parameters={"__array__": "categorical"},
    )
    records = ak.contents.RecordArray(
        [ak.contents.NumpyArray(np.array([4.0, 3.0, 1.0], dtype=np.int64))], ["x"]
    )
    result = ak.concatenate((numbers, records), highlevel=False)
    assert result.is_equal_to(
        ak.contents.UnionArray(
            ak.index.Index8([0, 0, 0, 1, 1, 1]),
            ak.index.Index64([0, 1, 2, 0, 1, 2]),
            [
                ak.contents.IndexedArray(
                    ak.index.Index64([0, 2, 3]),
                    ak.contents.NumpyArray(np.arange(10, dtype=np.int64)),
                    parameters={"__array__": "categorical"},
                ),
                ak.contents.RecordArray(
                    [ak.contents.NumpyArray(np.array([4.0, 3.0, 1.0], dtype=np.int64))],
                    ["x"],
                ),
            ],
        )
    )