docs: protected StreamRequestHandlerState determineRequestHandlerState(String itemTag) {
  
          if (keyIterator.hasNext() && !fetchedEnoughForAllPartitions()) {
              return StreamRequestHandlerState.WRITING;
          } else {
              logger.info("Finished fetch " + itemTag + " for store '" + storageEngine.getName()
                      + "' with partitions  " + partitionIds);
              progressInfoMessage("Fetch " + itemTag + " (end of scan)");
  
              return StreamRequestHandlerState.COMPLETE;
          }
      }