code: protected Queue<Object> getWorkQueue() {
          synchronized (this.queueLock) {
              // swap the primary and secondary queues
              Queue<Object> tmp = this.workQueue1;
              this.workQueue1 = this.workQueue2;
              this.workQueue2 = tmp;
              return tmp;
          } // end-sync
      }
docs: Access the current work queue of pending updates for the selector. This
  will cause further updates to go onto another queue until this method
  is called again.
  
  @return Queue<Object>