code: def render(self):
      # Don't try to render into closed windows
      if not self._window._context:
          return
  
      self._render_once()
  
      # Just keep rendering if we're paused, but hold onto control flow
      while self._pause_subject.value:
          self._render_once()
  
imports: import dm_control.viewer.application
  import glfw
label_desc: Use image node_id 1 for calling the DmControlViewer obj's underlying member method code with example usage: obj.render() without return types