docs: def meta_changed_notify_after(self, state_machine_m, _, info):
          """Handle notification about the change of a state's meta data
  
          The meta data of the affected state(s) are read and the view updated accordingly.
          :param StateMachineModel state_machine_m: Always the state machine model belonging to this editor
          :param str _: Always "state_meta_signal"
          :param dict info: Information about the change, contains the MetaSignalMessage in the 'arg' key value
          """
          meta_signal_message = info['arg']
          if meta_signal_message.origin == "graphical_editor_gaphas":  # Ignore changes caused by ourself
              return
          if meta_signal_message.origin == "load_meta_data":  # Meta data can't be applied, as the view has not yet
              return                                          # been created
          notification = meta_signal_message.notification
          if not notification:    # For changes applied to the root state, there are always two notifications
              return              # Ignore the one with less information
          if self.model.ongoing_complex_actions:
              return
  
          model = notification.model
          view = self.canvas.get_view_for_model(model)
  
          if meta_signal_message.change == 'show_content':
              library_state_m = model
              library_state_v = view
              if library_state_m.meta['gui']['show_content'] is not library_state_m.show_content():
                  logger.warning("The content of the LibraryState won't be shown, because "
                                 "MAX_VISIBLE_LIBRARY_HIERARCHY is 1.")
              if library_state_m.show_content():
                  if not library_state_m.state_copy_initialized:
                      logger.warning("Show library content without initialized state copy does not work {0}"
                                     "".format(library_state_m))
                  logger.debug("Show content of {}".format(library_state_m.state))
                  gui_helper_meta_data.scale_library_content(library_state_m)
                  self.add_state_view_for_model(library_state_m.state_copy, view,
                                                hierarchy_level=library_state_v.hierarchy_level + 1)
              else:
                  logger.debug("Hide content of {}".format(library_state_m.state))
                  state_copy_v = self.canvas.get_view_for_model(library_state_m.state_copy)
                  if state_copy_v:
                      state_copy_v.remove()
          else:
              if isinstance(view, StateView):
                  view.apply_meta_data(recursive=meta_signal_message.affects_children)
              else:
                  view.apply_meta_data()
  
          self.canvas.request_update(view, matrix=True)
          self.canvas.wait_for_update()