code: private void parseBodyMultipart() {
          if (undecodedChunk == null || undecodedChunk.readableBytes() == 0) {
              // nothing to decode
              return;
          }
          InterfaceHttpData data = decodeMultipart(currentStatus);
          while (data != null) {
              addHttpData(data);
              if (currentStatus == MultiPartStatus.PREEPILOGUE || currentStatus == MultiPartStatus.EPILOGUE) {
                  break;
              }
              data = decodeMultipart(currentStatus);
          }
      }
docs: Parse the Body for multipart
  
  @throws ErrorDataDecoderException
  if there is a problem with the charset decoding or other
  errors