old_contents: from __future__ import print_function
  from __future__ import absolute_import
  from __future__ import division
  
  import compas_rhino
  from compas.artists import Artist
  
  
  class RhinoArtist(Artist):
      """Base class for all Rhino artists.
  
      Attributes
      ----------
      guids : list
          A list of the GUID of the Rhino objects created by the artist.
  
      """
  
      def __init__(self):
          self._guids = []
  
      def redraw(self):
          compas_rhino.rs.EnableRedraw(True)
          compas_rhino.rs.Redraw()
  
      def clear(self):
          if not self._guids:
              return
          compas_rhino.delete_objects(self._guids)
          self._guids = []
  
new_contents: from __future__ import print_function
  from __future__ import absolute_import
  from __future__ import division
  
  import compas_rhino
  from compas.artists import Artist
  
  
  class RhinoArtist(Artist):
      """Base class for all Rhino artists.
      """
  
      def clear_layer(self):
          if self.layer:
              compas_rhino.clear_layer(self.layer)
  
subject: simplify base rhino artist