How to use the etlhelper.db_helper_factory.DB_HELPER_FACTORY.helpers.keys function in etlhelper

def validate_params(self):
        """
        Validate database parameters.

        Should validate that a dbtype is a valid one and that the appropriate
        params have been passed for a particular db_type.

        :raises ETLHelperParamsError: Error if params are invalid
        """
        # Get a set of the attributes to compare against required attributes.
        given = set(self.keys())

        try:
            required_params = DB_HELPER_FACTORY.from_dbtype(self.dbtype).required_params
        except ETLHelperHelperError:
            msg = f'{self.dbtype} not in valid types ({DB_HELPER_FACTORY.helpers.keys()})'
            raise ETLHelperDbParamsError(msg)

        unset_params = (given ^ required_params) & required_params
        if unset_params:
            msg = f'{unset_params} not set. Required parameters are {required_params}'
            raise ETLHelperDbParamsError(msg)