def METHOD_NAME(self):
    from ilastik.workflows.carving.carvingTools import parallel_watershed
    shape = (400,) * 2
    x = numpy.random.rand(*shape).astype("float32")
    seg, max_id = parallel_watershed(x, max_workers=4)
    max_expected = seg.max()
    assert max_id == max_expected, f"Expect {max_expected} but got {max_id}"
    assert max_id > 1, f"Expect more than one segment in watershed result"
    # TODO test that labels in individual blocks are indeed different