code: protected <T, A> void handleMessage(final Channel channel, final DataInput message, final ManagementRequestHeader header, ManagementRequestHandler<T, A> handler) throws IOException {
          final ActiveOperation<T, A> support = getActiveOperation(header);
          if(support == null) {
              throw ProtocolLogger.ROOT_LOGGER.responseHandlerNotFound(header.getBatchId());
          }
          handleMessage(channel, message, header, support, handler);
      }
docs: Handle a message.
  
  @param channel the channel
  @param message the message
  @param header the protocol header
  @param handler the request handler
  @throws IOException