docs: def _produce_return(self, cursor):
          """ Return the one result.
          """
          results = cursor.fetchmany(2)
          if len(results) != 1:
              return None
  
          # Return the one row, or the one column.
          row = results[0]
          if self._row_formatter is not None:
              row = self._row_formatter(row, cursor)
          elif len(row) == 1:
              row = row[0]
  
          return row