code: def _first_as_df(self):
          
          columns = self._schema_rdd.columns
          df = pd.DataFrame.from_records(
              [self._schema_rdd.first()],
              columns=self._schema_rdd.columns)
          df = _update_index_on_df(df, self._index_names)
          return df
docs: Gets the first row as a Panda's DataFrame. Useful for functions like
          dtypes & ftypes