def stop_reactor():
    """Stop the reactor and join the reactor thread until it stops.
    Call this function in teardown at the module or package level to
    reset the twisted system after your tests. You *must* do this if
    you mix tests using these tools and tests using twisted.trial.
    """
    global _twisted_thread

    def stop_reactor():
        '''Helper for calling stop from withing the thread.'''
        reactor.stop()

    reactor.callFromThread(stop_reactor)
    reactor_thread.join()
    for p in reactor.getDelayedCalls():
        if p.active():
            p.cancel()
    _twisted_thread = None
Stop the reactor and join the reactor thread until it stops.
    Call this function in teardown at the module or package level to
    reset the twisted system after your tests. You *must* do this if
    you mix tests using these tools and tests using twisted.trial.