def execute(self, transition):
self._transitions.append(transition)<EOL>if self._thread is None or not self._thread.isAlive():<EOL><INDENT>self._thread = threading.Thread(target=self._transition_loop)<EOL>self._thread.setDaemon(True)<EOL>self._thread.start()<EOL><DEDENT>
Queue a transition for execution.

:param transition: The transition