docs: def execute(self, transition):
          """
          Queue a transition for execution.
  
          :param transition: The transition
          """
          self._transitions.append(transition)
          if self._thread is None or not self._thread.isAlive():
              self._thread = threading.Thread(target=self._transition_loop)
              self._thread.setDaemon(True)
              self._thread.start()