code: void enqueue(ServerRequest request) {
          synchronized (reqQueueLockObject) {
              if (request != null) {
                  queue.add(request);
                  if (getSize() >= MAX_ITEMS) {
                      queue.remove(1);
                  }
                  persist();
              }
          }
      }
docs: <p>Adds a {@link ServerRequest} object to the queue.</p>
  
  @param request The {@link ServerRequest} object to add to the queue.