code: def show_bundles(
      bundles,
      interactive=True,
      view="sagital",
      colors=None,
      linewidth=0.3,
      save_as=None,
  ):
      """Render bundles to visualize them interactively or save them into a png.
  
      The function allows to just render the bundles in an interactive plot or
      to export them into a png file.
  
      Parameters
      ----------
      bundles : list
          Bundles to be rendered.
      interactive : boolean, optional
          If True a 3D interactive rendering is created. Default is True.
      view : str, optional
          Viewing angle. Supported options: 'sagital','axial' and 'coronal'.
          Default is 'sagital'.
      colors : list, optional
         Colors to be used for each bundle. If None default colors are used.
      linewidth : float, optional
          Width of each rendered streamline. Default is 0.3.
      save_as : str, optional
          If not None rendered scene is stored in a png file with that name.
          Default is None.
  
      """
      scene = window.Scene()
      scene.SetBackground(1.0, 1, 1)
  
      for i, bundle in enumerate(bundles):
          if colors is None:
              lines_actor = actor.streamtube(
                  bundle, linewidth=linewidth
              )
          else:
              lines_actor = actor.streamtube(
                  bundle, linewidth=linewidth, colors=colors[i]
              )
          if view == "sagital":
              lines_actor.RotateX(-90)
              lines_actor.RotateZ(90)
          elif view == "axial":
              pass
          elif view == "coronal":
              lines_actor.RotateX(-90)
          else:
              raise ValueError(
                  "Invalid view argument value. Use 'sagital',"
                  + "'axial' or 'coronal'."
              )
  
          scene.add(lines_actor)
  
      if interactive:
          window.show(scene)
  
      if save_as is not None:
          window.record(
              scene, n_frames=1, out_path=save_as, size=(900, 900)
          )
  
imports: from dipy.utils.optpkg import optional_package
label_desc: Use image node_id 1 for calling a global function with example usage: show_bundles(bundles, interactive, view, colors, linewidth, save_as) without return types