code: def append(self, obj):
          
          if isinstance(obj, dict) and self._col_names:
              obj = [obj.get(col, None) for col in self._col_names]
          assert isinstance(obj, list), \
              "obj appended to ReprListList needs to be a list or dict"
          self._original.append(obj)
docs: If it is a list it will append the obj, if it is a dictionary
          it will convert it to a list and append
          :param obj: dict or list of the object to append
          :return: None