Return the URL for the action.

        :param str endpoint: The controller
        :param str action: The action provided by the controller
        :param url_args: Additional endpoints(for endpoints that take part of
                         the url as option)
        :return: Full URL for the requested action

def _endpoint(self, endpoint, action, *url_args):
        """Return the URL for the action.

        :param str endpoint: The controller
        :param str action: The action provided by the controller
        :param url_args: Additional endpoints(for endpoints that take part of
                         the url as option)
        :return: Full URL for the requested action
        """
        args = (self.api_base, endpoint, action)
        if action == '':
            args = (self.api_base, endpoint)
        api_url = "/".join(args)
        if url_args:
            if len(url_args) == 1:
                api_url += "/" + url_args[0]
            else:
                api_url += "/".join(url_args)
        return api_url