def test_shuffled_fields(dataset_num_files_1, reader_factory):
    """Test to verify not sorted keys for fields argument in ngrams work."""
    fields = {
        2: [TestSchema.id, TestSchema.id2, TestSchema.image_png, TestSchema.matrix],
        -1: [TestSchema.id, TestSchema.id2, TestSchema.sensor_name],
    }
    _test_continuous_ngram_tf(fields, dataset_num_files_1, reader_factory)
Test to verify not sorted keys for fields argument in ngrams work.
petastorm/tests/test_ngram_end_to_end.py