code: int refreshAndGetMin() {
  		int min = Integer.MAX_VALUE;
  
  		ResultSubpartition[] allPartitions = partition.getAllPartitions();
  		if (allPartitions.length == 0) {
  			// meaningful value when no channels exist:
  			return 0;
  		}
  
  		for (ResultSubpartition part : allPartitions) {
  			int size = part.unsynchronizedGetNumberOfQueuedBuffers();
  			min = Math.min(min, size);
  		}
  
  		return min;
  	}
docs: Iterates over all sub-partitions and collects the minimum number of queued buffers in a
  sub-partition in a best-effort way.
  
  @return minimum number of queued buffers per sub-partition (<tt>0</tt> if sub-partitions exist)