code: public void pause(Boolean pausePlayback, int position) {
          IConnection conn = Red5.getConnectionLocal();
          if (conn instanceof IStreamCapableConnection) {
              IStreamCapableConnection streamConn = (IStreamCapableConnection) conn;
              Number streamId = conn.getStreamId();
              IClientStream stream = streamConn.getStreamById(streamId);
              if (stream != null && stream instanceof ISubscriberStream) {
                  ISubscriberStream subscriberStream = (ISubscriberStream) stream;
                  // pausePlayback can be "null" if "pause" is called without any parameters from flash
                  if (pausePlayback == null) {
                      pausePlayback = !subscriberStream.isPaused();
                  }
                  if (pausePlayback) {
                      subscriberStream.pause(position);
                  } else {
                      subscriberStream.resume(position);
                  }
              }
          }
      }
docs: Pause at given position. Required as "pausePlayback" can be "null" if no flag is passed by the client
  
  @param pausePlayback
  Pause playback or not
  @param position
  Pause position