List the subscriptions currently active

async def _get_subscriptions(self) -> Tuple[Set[Text], Text]:
        """
        List the subscriptions currently active
        """

        url, params = self._get_subscriptions_endpoint()

        get = self.session.get(url, params=params)

        async with get as r:
            await self._handle_fb_response(r)
            data = await r.json()

            for scope in data['data']:
                if scope['object'] == 'page':
                    return (
                        set(x['name'] for x in scope['fields']),
                        scope['callback_url'],
                    )

        return set(), ''