code: def testExtractMultipleDrumTracks(self):
      music_testing_lib.add_track_to_sequence(
          self.note_sequence,
          0,
          [(12, 100, 2, 4), (11, 1, 6, 11)],
          is_drum=True,
      )
      music_testing_lib.add_track_to_sequence(
          self.note_sequence,
          1,
          [
              (12, 127, 2, 4),
              (14, 50, 6, 8),
              (50, 100, 33, 37),
              (52, 100, 37, 38),
          ],
          is_drum=True,
      )
      quantized_sequence = sequences_lib.quantize_note_sequence(
          self.note_sequence, steps_per_quarter=1
      )
      expected = [
          [
              NO_DRUMS,
              NO_DRUMS,
              DRUMS(12),
              NO_DRUMS,
              NO_DRUMS,
              NO_DRUMS,
              DRUMS(11, 14),
          ],
          [
              NO_DRUMS,
              DRUMS(50),
              NO_DRUMS,
              NO_DRUMS,
              NO_DRUMS,
              DRUMS(52),
          ],
      ]
      drum_tracks, _ = drum_pipelines.extract_drum_tracks(
          quantized_sequence, min_bars=1, gap_bars=2
      )
      drum_tracks = sorted([list(drums) for drums in drum_tracks])
      self.assertEqual(expected, drum_tracks)
  
file_path: magenta/magenta/pipelines/drum_pipelines_test.py
imports: from absl.testing import absltest
  from magenta.common import testing_lib
  from magenta.pipelines import drum_pipelines
  from note_seq import drums_lib
  from note_seq import sequences_lib
  from note_seq import testing_lib
  from note_seq.protobuf import music_pb2
label_desc: Use image node_id 5 for calling the DrumPipelinesTest obj's underlying member method code with example usage: obj.testExtractMultipleDrumTracks() without return types