code: def pack(self, value=None):
          
          buff = self.body
          if not value:
              value = self.body
  
          if value:
              if isinstance(value, (list, FixedTypeList)):
                  obj = self._get_body_instance()
                  obj.extend(value)
              elif hasattr(value, 'pack'):
                  obj = value
  
              self.body = obj.pack()
  
          multipart_packed = super().pack()
          self.body = buff
  
          return multipart_packed
docs: Pack a StatsReply using the object's attributes.
  
          This method will pack the attribute body and multipart_type before pack
          the StatsReply object, then will return this struct as a binary data.
  
          Returns:
              stats_reply_packed (bytes): Binary data with StatsReply packed.