code: private static void fireErrorReceivingResponseEvent(OperationContext opContext, HttpURLConnection request,
              RequestResult result) {
          if (opContext.getErrorReceivingResponseEventHandler().hasListeners()
                  || OperationContext.getGlobalErrorReceivingResponseEventHandler().hasListeners()) {
              ErrorReceivingResponseEvent event = new ErrorReceivingResponseEvent(opContext, request, result);
              opContext.getErrorReceivingResponseEventHandler().fireEvent(event);
              OperationContext.getGlobalErrorReceivingResponseEventHandler().fireEvent(event);
          }
      }
docs: Fires events representing that an error occurred when receiving the response.