code: protected Collector<OT> createWorksetUpdateOutputCollector(Collector<OT> delegate) {
  		DataOutputView outputView = worksetBackChannel.getWriteEnd();
  		TypeSerializer<OT> serializer = getOutputSerializer();
  		return new WorksetUpdateOutputCollector<OT>(outputView, serializer, delegate);
  	}
docs: Creates a new {@link WorksetUpdateOutputCollector}.
  
  <p>This collector is used by {@link IterationIntermediateTask} or {@link IterationTailTask} to update the
  workset.
  
  <p>If a non-null delegate is given, the new {@link Collector} will write to the solution set and also call
  collect(T) of the delegate.
  
  @param delegate null -OR- the delegate on which to call collect() by the newly created collector
  @return a new {@link WorksetUpdateOutputCollector}