code: private void readObject(java.io.ObjectInputStream s)
          throws java.io.IOException, ClassNotFoundException {
          s.defaultReadObject();
          for (;;) {
              @SuppressWarnings("unchecked")
              E item = (E) s.readObject();
              if (item == null)
                  break;
              else
                  offer(item);
          }
      }
docs: Reconstitutes the Queue instance from a stream (that is,
  deserializes it).
  
  @param s the stream