code: def connection(self):
          
          if not self._connection:
              logger.debug('Opening connection to: {}'.format(self.dsn))
              self._connection = self.engine.connect()
              logger.debug('Opened connection to: {}'.format(self.dsn))
  
          # logger.debug("Opening connection to: {}".format(self.dsn))
          return self._connection
docs: Return an SqlAlchemy connection.