code: @Override
      public boolean offer(T t) {
          if (t == null) {
              throw new IllegalArgumentException();
          }
  
          boolean ret = false;
          synchronized (lock) {
              if (t instanceof QueueItem && ((QueueItem) t).isExpedited()) {
  
                  if (numberOfUsedExpeditedSlots.get() < expeditedBuffer.length) {
                      expeditedInsert(t);
                      numberOfUsedExpeditedSlots.getAndIncrement();
                      ret = true;
                  }
              } else {
                  if (numberOfUsedSlots.get() < buffer.length) {
                      insert(t);
                      numberOfUsedSlots.getAndIncrement();
                      ret = true;
                  }
              }
          }
  
          if (ret) {
              notifyGet_();
              return true;
          }
  
          return false;
      }
docs: /*
  @awisniew - ADDED
  
  (non-Javadoc)
  
  @see java.util.concurrent.BlockingQueue#offer(java.lang.Object)