docs: def switch_state_machine_execution_engine(self, new_state_machine_execution_engine):
          """
          Switch the state machine execution engine the main window controller listens to.
          :param new_state_machine_execution_engine: the new state machine execution engine for this controller
          :return:
          """
          # relieve old one
          self.relieve_model(self.state_machine_execution_model)
  
          # register new
          self.state_machine_execution_model = new_state_machine_execution_engine
          self.observe_model(self.state_machine_execution_model)