code: def __expand(self):
      centroid_actors = self.__clusters_visualizer.centroid_actors
      lengths = self.__clusters_visualizer.lengths
      sizes = self.__clusters_visualizer.sizes
      min_length = np.min(lengths)
      min_size = np.min(sizes)
      for cent in centroid_actors:
          if centroid_actors[cent]["selected"]:
              if not centroid_actors[cent]["expanded"]:
                  len_ = centroid_actors[cent]["length"]
                  sz_ = centroid_actors[cent]["size"]
                  if len_ >= min_length and sz_ >= min_size:
                      centroid_actors[cent]["actor"].VisibilityOn()
                      cent.VisibilityOff()
                      centroid_actors[cent]["expanded"] = 1
      self.show_m.render()
  
imports: from packaging.version import Version
  import warnings
  import numpy
  from dipy import __version__
  from dipy.io.stateful_tractogram import Space, StatefulTractogram
  from dipy.io.streamline import save_tractogram
  from dipy.tracking.streamline import Streamlines
  from dipy.utils.optpkg import optional_package
  from dipy.viz.gmem import GlobalHorizon
  from dipy.viz.horizon.tab import ClustersTab, PeaksTab, ROIsTab, SlicesTab, TabManager, build_label
  from dipy.viz.horizon.visualizer import ClustersVisualizer, SlicesVisualizer
  from dipy.viz.horizon.util import check_img_dtype, check_img_shapes
label_desc: Use image node_id 2 for calling the Horizon obj's underlying member method code with example usage: obj.__expand() without return types