docs: protected static <T, A> ManagementRequestHandler<T, A> getFallbackHandler(final ManagementRequestHeader header) {
          return new ManagementRequestHandler<T, A>() {
              @Override
              public void handleRequest(final DataInput input, ActiveOperation.ResultHandler<T> resultHandler, ManagementRequestContext<A> context) throws IOException {
                  final Exception error = ProtocolLogger.ROOT_LOGGER.noSuchResponseHandler(Integer.toHexString(header.getRequestId()));
                  if(resultHandler.failed(error)) {
                      safeWriteErrorResponse(context.getChannel(), context.getRequestHeader(), error);
                  }
              }
          };
      }