docs: def _sqlalchemy_on_finish(self):
          """
          Closes the sqlalchemy transaction. Rolls back if an error occurred.
          """
  
          if hasattr(self, "_db_conns"):
              try:
                  if self.get_status() >= 200 and self.get_status() <= 399:
                      for db_conn in self._db_conns.values():
                          db_conn.commit()
                  else:
                      for db_conn in self._db_conns.values():
                          db_conn.rollback()
              except:
                  tornado.log.app_log.warning("Error occurred during database transaction cleanup: %s", str(sys.exc_info()[0]))
                  raise
              finally:
                  for db_conn in self._db_conns.values():
                      try:
                          db_conn.close()
                      except:
                          tornado.log.app_log.warning("Error occurred when closing the database connection", exc_info=True)