code: def show_both_bundles(bundles, colors=None, show=True, fname=None):
      scene = window.Scene()
      scene.SetBackground(1.0, 1, 1)
      for i, bundle in enumerate(bundles):
          color = colors[i]
          lines_actor = actor.streamtube(bundle, color, linewidth=0.3)
          lines_actor.RotateX(-90)
          lines_actor.RotateZ(90)
          scene.add(lines_actor)
      if show:
          window.show(scene)
      if fname is not None:
          sleep(1)
          window.record(
              scene, n_frames=1, out_path=fname, size=(900, 900)
          )
  
imports: from time import sleep
  from dipy.align.streamlinear import StreamlineLinearRegistration
  from dipy.data import two_cingulum_bundles
  from dipy.tracking.streamline import set_number_of_points
  from dipy.viz import window, actor
label_desc: Use image node_id 1 for calling a global function with example usage: show_both_bundles(bundles, colors, show, fname) without return types