Generator that allows to iterate per API keys associated to an api_id and a stage_name.

def get_api_keys(self, api_id, stage_name):
        """
        Generator that allows to iterate per API keys associated to an api_id and a stage_name.
        """
        response = self.apigateway_client.get_api_keys(limit=500)
        stage_key = '{}/{}'.format(api_id, stage_name)
        for api_key in response.get('items'):
            if stage_key in api_key.get('stageKeys'):
                yield api_key.get('id')