code: private static void resetContentReaderIndex(BinaryRequest request) {
          ByteBuf content = contentFromWriteRequest(request);
          if (content != null) {
              try {
                  content.readerIndex(0);
              } catch (Exception ex) {
                  LOGGER.warn("Exception while resetting the content reader index to 0, " +
                      "please report this as a bug.", ex);
              }
          }
      }
docs: Helper method to reset the reader index of the content so if downstream components
  on outbound did modify it, it can be reused (looking at you, SSLHandler).
  
  @param request the request which may have content that needs to be reset.