code: def _dump_to_text(self, with_stats):
          
          return tc.extensions._xgboost_dump_model(self.__proxy__, with_stats=with_stats, format='text')
docs: Dump the models into a list of strings. Each
          string is a text representation of a tree.
  
          Parameters
          ----------
          with_stats : bool
              If true, include node statistics in the output.
  
          Returns
          -------
          out : SFrame
              A table with two columns: feature, count,
              ordered by 'count' in descending order.