code: def get_sleep_timer(self):
          
          resp = self.avTransport.GetRemainingSleepTimerDuration([
              ('InstanceID', 0),
          ])
          if resp['RemainingSleepTimerDuration']:
              times = resp['RemainingSleepTimerDuration'].split(':')
              return (int(times[0]) * 3600 +
                      int(times[1]) * 60 +
                      int(times[2]))
          else:
              return None
docs: Retrieves remaining sleep time, if any
  
          Returns:
              int or NoneType: Number of seconds left in timer. If there is no
                  sleep timer currently set it will return None.