def METHOD_NAME(graph_data_loader):
    sample = np.array([['a','b','d'], ['a','b','d']])
    sample_inds = graph_data_loader.backend.mapper.get_indexes(sample, type_of="t")
    subjects = graph_data_loader.get_complementary_subjects(sample_inds)
    expected = [[0, 1],[0, 1]]
    assert [set(x) for x in subjects] == [set(x) for x in expected], "Subjects differ, expected {}, instead got {}.".format(expected, subjects)