code: @Override
  	protected ThreadBase<E> getSpillingThread(ExceptionHandler<IOException> exceptionHandler, CircularQueues<E> queues,
  			AbstractInvokable parentTask, MemoryManager memoryManager, IOManager ioManager, 
  			TypeSerializerFactory<E> serializerFactory, TypeComparator<E> comparator,
  			List<MemorySegment> sortReadMemory, List<MemorySegment> writeMemory, int maxFileHandles)
  	{
  		this.bufferIterator = new BufferQueueIterator(queues);
  		setResultIterator(this.bufferIterator);
  		
  		return null;
  	}
docs: /*
  This method does not actually create a spilling thread, but grabs the circular queues and creates the
  iterator that reads from the sort buffers in turn.