code: protected void setLastOutputCollector(Collector<OT> newOutputCollector) {
  		int numChained = this.chainedTasks.size();
  
  		if (numChained == 0) {
  			output = newOutputCollector;
  			return;
  		}
  
  		chainedTasks.get(numChained - 1).setOutputCollector(newOutputCollector);
  	}
docs: Sets the last output {@link Collector} of the collector chain of this {@link BatchTask}.
  <p>
  In case of chained tasks, the output collector of the last {@link ChainedDriver} is set. Otherwise it is the
  single collector of the {@link BatchTask}.
  
  @param newOutputCollector new output collector to set as last collector