code: def fetchone(self, sql: str, *args) -> Optional[Sequence[Any]]:
          
          self.ensure_db_open()
          cursor = self.db.cursor()
          self.db_exec_with_cursor(cursor, sql, *args)
          try:
              return cursor.fetchone()
          except:  # nopep8
              log.exception("fetchone: SQL was: " + sql)
              raise
docs: Executes SQL; returns the first row, or None.