def _create_scene(self, num_tracks = None):
     if self._scene_count == -1:
         sc = SceneComponent(self._num_tracks, self.tracks_to_use, self._scene_count)
     else:
         sc = LC2SceneComponent(self._num_tracks, self.tracks_to_use, self._scene_count)
     self._scene_count += 1
     return sc
 def _create_scene(self):
     return SceneComponent(self._num_tracks, self.tracks_to_use)