code: def __init__(self):
      # window level sharing
      self.window_timer_cnt = 0
  
      # slicer level sharing
      self.slicer_opacity = 1
      self.slicer_colormap = "gray"
      self.slicer_colormaps = [
          "gray",
          "magma",
          "viridis",
          "jet",
          "Pastel1",
          "disting",
      ]
      self.slicer_colormap_cnt = 0
      self.slicer_axes = ["x", "y", "z"]
  
      self.slicer_curr_x = None
      self.slicer_curr_y = None
      self.slicer_curr_z = None
  
      self.slicer_curr_actor_x = None
      self.slicer_curr_actor_y = None
      self.slicer_curr_actor_z = None
  
      self.slicer_orig_shape = None
      self.slicer_resliced_shape = None
  
      self.slicer_vol_idx = None
      self.slicer_vol = None
  
      self.slicer_peaks_actor_z = None
      self.slicer_rgb = False
  
      self.slicer_grid = False
  
      # tractogram level sharing
      self.cluster_thr = 15
      # self.cluster_lengths = []  # not used
      # self.cluster_sizes = []  # not used
      # self.cluster_thr_min_max = []  # not used
      self.streamline_actors = []
      self.centroid_actors = []
      self.cluster_actors = []
  
label_desc: Use image node_id 1 to create a new GlobalHorizon object  with example: obj = GlobalHorizon()