code: def create_query_engine(config, clazz):
      
      try:
          qe = clazz(**config.settings)
      except Exception as err:
          raise CreateQueryEngineError(clazz, config.settings, err)
      return qe
docs: Create and return new query engine object from the
      given `DBConfig` object.
  
      :param config: Database configuration
      :type config: dbconfig.DBConfig
      :param clazz: Class to use for creating query engine. Should
                    act like query_engine.QueryEngine.
      :type clazz: class
      :return: New query engine