code: def add_actor(self, uinput, reset_camera=False, name=None, loc=None,
                    culling=False):
          
          # add actor to the correct render window
          self._active_renderer_index = self.loc_to_index(loc)
          renderer = self.renderers[self._active_renderer_index]
          return renderer.add_actor(uinput, reset_camera, name, culling)
docs: Adds an actor to render window.  Creates an actor if input is
          a mapper.
  
          Parameters
          ----------
          uinput : vtk.vtkMapper or vtk.vtkActor
              vtk mapper or vtk actor to be added.
  
          reset_camera : bool, optional
              Resets the camera when true.
  
          loc : int, tuple, or list
              Index of the renderer to add the actor to.  For example,
              ``loc=2`` or ``loc=(1, 1)``.  If None, selects the last
              active Renderer.
  
          culling : bool optional
              Does not render faces that should not be visible to the
              plotter.  This can be helpful for dense surface meshes,
              especially when edges are visible, but can cause flat
              meshes to be partially displayed.  Default False.
  
          Returns
          -------
          actor : vtk.vtkActor
              The actor.
  
          actor_properties : vtk.Properties
              Actor properties.