'Stop our callback\'s background task thread.'

def stop(self):

    if (self.thread is None):
        self.bus.log((('No    thread    running    for    %s.' % self.name) or self.__class__.__name__))
    else:
        if (self.thread is not threading.currentThread()):
            name = self.thread.getName()
            self.thread.cancel()
            if (not get_daemon(self.thread)):
                self.bus.log(('Joining    %r' % name))
                self.thread.join()
            self.bus.log(('Stopped    thread    %r.' % name))
        self.thread = None
