docs: protected MultiThreadedWorker getMultiThreadedWorker(SelectionKey key, long threadIdfWQM) {
  
          MultiThreadedWorker worker = null;
          synchronized (multiThreadedObjectPool) {
              worker = (MultiThreadedWorker) multiThreadedObjectPool.get();
          }
  
          if (worker == null) {
              worker = new MultiThreadedWorker(this);
          }
  
          worker.set(key);
          return worker;
      }