code: public RequestPayload generateRequestPayload(Request request) {
          if (payloads.size() + 1 > expectCount) {
              throw new TooManyRequestsException(this, request);
          }
          RequestPayload requestPayload = new RequestPayload(inspections);
          requests.put(requestPayload.getSerialId(), request);
          payloads.put(requestPayload.getSerialId(), null);
          return requestPayload;
      }
docs: /*
  (non-Javadoc)
  @see org.jboss.arquillian.warp.impl.client.execution.WarpGroup#generateRequestPayload()