code: def set_meta(self, total_length, object_name):
          
          self.total_length = total_length
          self.object_name = object_name
          self.prefix = self.object_name + ': ' if self.object_name else ''
docs: Metadata settings for the object. This method called before uploading object
          :param total_length: Total length of object.
          :param object_name: Object name to be showed.