docs: def register_view(self, view):
          """Called when the View was registered"""
          super(StateMachinesEditorController, self).register_view(view)
          self.view['notebook'].connect('switch-page', self.on_switch_page)
  
          # Add all already open state machines
          for state_machine in self.model.state_machines.values():
              self.add_graphical_state_machine_editor(state_machine)