Fetch the value of specified fields in order to avoid setting the same
        field twice at the same value (since Facebook engineers are not able
        to make menus that keep on working if set again).

async def _get_messenger_profile(self, page, fields: List[Text]):
        """
        Fetch the value of specified fields in order to avoid setting the same
        field twice at the same value (since Facebook engineers are not able
        to make menus that keep on working if set again).
        """

        params = {
            'access_token': page['page_token'],
            'fields': ','.join(fields),
        }

        get = self.session.get(PROFILE_ENDPOINT, params=params)
        async with get as r:
            await self._handle_fb_response(r)

            out = {}

            for data in (await r.json())['data']:
                out.update(data)

            return out