code: List<IntermediateResultPartition> finishAllBlockingPartitions() {
  		List<IntermediateResultPartition> finishedBlockingPartitions = null;
  
  		for (IntermediateResultPartition partition : resultPartitions.values()) {
  			if (partition.getResultType().isBlocking() && partition.markFinished()) {
  				if (finishedBlockingPartitions == null) {
  					finishedBlockingPartitions = new LinkedList<IntermediateResultPartition>();
  				}
  
  				finishedBlockingPartitions.add(partition);
  			}
  		}
  
  		if (finishedBlockingPartitions == null) {
  			return Collections.emptyList();
  		}
  		else {
  			return finishedBlockingPartitions;
  		}
  	}
docs: Returns all blocking result partitions whose receivers can be scheduled/updated.