def init_app(self, app):
        """
        An alternative way to pass your :class:`flask.Flask` application
        object to Flask-S3. :meth:`init_app` also takes care of some
        default `settings`_.

        :param app: the :class:`flask.Flask` application object.
        """

        for k, v in DEFAULT_SETTINGS.items():
            app.config.setdefault(k, v)

        if app.debug and not get_setting('FLASKS3_DEBUG', app):
            app.config['FLASKS3_ACTIVE'] = False

        if get_setting('FLASKS3_ACTIVE', app):
            app.jinja_env.globals['url_for'] = url_for
        if get_setting('FLASKS3_USE_CACHE_CONTROL', app) and app.config.get('FLASKS3_CACHE_CONTROL'):
            cache_control_header = get_setting('FLASKS3_CACHE_CONTROL', app)
            app.config['FLASKS3_HEADERS']['Cache-Control'] = cache_control_header
An alternative way to pass your :class:`flask.Flask` application
        object to Flask-S3. :meth:`init_app` also takes care of some
        default `settings`_.

        :param app: the :class:`flask.Flask` application object.