def METHOD_NAME(lt_ctx):
    data = _mk_random(size=(16, 16, 16, 16), dtype="float32")
    dataset = lt_ctx.load(
        "memory",
        data=data,
        tileshape=(7, 16, 16),
        num_partitions=2,
        sig_dims=2
    )
    pixelsum = PixelsumFrameUDF()
    res = lt_ctx.run_udf(dataset=dataset, udf=pixelsum)
    assert np.allclose(res['pixelsum_nav'].data, np.sum(data, axis=(2, 3)))
    assert np.allclose(res['pixelsum_nav_raw'].data.reshape((16, 16)), np.sum(data, axis=(2, 3)))
    assert np.allclose(res['pixelsum_sig'].data, np.sum(data, axis=(0, 1)))
    assert np.allclose(res['pixelsum_sig_raw'].data, np.sum(data, axis=(0, 1)))