Shortcut to access the config in your class
        :param key: The key to access
        :param default: The default value when None
        :returns mixed:

def config_(cls, key, default=None):
        """
        Shortcut to access the config in your class
        :param key: The key to access
        :param default: The default value when None
        :returns mixed:
        """
        return cls._app.config.get(key, default)