def help_center_articles_labels_list(self, locale=None, **kwargs):
        "https://developer.zendesk.com/rest_api/docs/help_center/labels#list-all-labels"
        api_path = "/api/v2/help_center/articles/labels.json"
        if locale:
            api_opt_path = "/api/v2/help_center/{locale}/articles/labels.json"
            api_path = api_opt_path.format(locale=locale)
        return self.call(api_path, **kwargs)
https://developer.zendesk.com/rest_api/docs/help_center/labels#list-all-labels