code: @Override
      public void processOutput(Map<String, String> resultsMap) {
          queue.add(resultsMap);
  
          if (queue.size() > 10000) {
              log.info("Queue size " + queue.size() + ", waiting");
              try {
                  Thread.sleep(500);
              } catch (InterruptedException ex) {
                  log.info("Interrupted ", ex);
              }
          }
      }
docs: Stores the output from a Frontier into the queue, pausing and waiting if the given queue is too large
  
  @param resultsMap map of String and String representing the output of a Frontier's DFS