docs: def state(self):
          """Which state the session is in.
  
          Starting - all messages needed to get stream started.
          Playing - keep-alive messages every self.session_timeout.
          """
          if self.method in ['OPTIONS', 'DESCRIBE', 'SETUP', 'PLAY']:
              state = STATE_STARTING
          elif self.method in ['KEEP-ALIVE']:
              state = STATE_PLAYING
          else:
              state = STATE_STOPPED
          _LOGGER.debug('RTSP session (%s) state %s', self.host, state)
          return state