code: void retriggerSubpartitionRequest(Timer timer, final int subpartitionIndex) {
  		synchronized (requestLock) {
  			checkState(subpartitionView == null, "already requested partition");
  
  			timer.schedule(new TimerTask() {
  				@Override
  				public void run() {
  					try {
  						requestSubpartition(subpartitionIndex);
  					} catch (Throwable t) {
  						setError(t);
  					}
  				}
  			}, getCurrentBackoff());
  		}
  	}
docs: Retriggers a subpartition request.