code: synchronized ResourceRequestEvent satisfyOne() {
      final ResourceRequest req = this.requestQueue.element();
      req.satisfyOne();
      if (req.isSatisfied()) {
        this.requestQueue.poll();
      }
      return req.getRequestProto();
    }
docs: Satisfies one resource for the front-most request. If that satisfies the
  request, it is removed from the queue.