How to use the pyatv.dmap.tags.string_tag function in pyatv

def test_parse_strings(self):
        in_data = tags.string_tag('stra', '') + \
                  tags.string_tag('strb', 'test string')
        parsed = parser.parse(in_data, lookup_tag)
        self.assertEqual(2, len(parsed))
        self.assertEqual('', parser.first(parsed, 'stra'))
        self.assertEqual('test string', parser.first(parsed, 'strb'))

revision = int(request.rel_url.query['revision-number'])
        if playing.revision != revision:
            # Not a valid response as a real device, just to make tests fail
            return web.Response(status=500)

        if playing.paused is not None:
            body += tags.uint32_tag('caps', 3 if playing.paused else 4)

        if playing.title is not None:
            body += tags.string_tag('cann', playing.title)

        if playing.artist is not None:
            body += tags.string_tag('cana', playing.artist)

        if playing.album is not None:
            body += tags.string_tag('canl', playing.album)

        if playing.genre is not None:
            body += tags.string_tag('cang', playing.genre)

        if playing.total_time is not None:
            total_time = playing.total_time * 1000  # sec -> ms
            body += tags.uint32_tag('cast', total_time)

            if playing.position is not None:
                pos = (playing.total_time - playing.position)
                body += tags.uint32_tag('cant', pos*1000)  # sec -> ms

        if playing.mediakind is not None:
            body += tags.uint32_tag('cmmk', playing.mediakind)

        if playing.playstatus is not None:

self._verify_auth_parameters(request)

        body = b''
        playing = self._get_response('playing')

        # Make sure revision matches
        revision = int(request.rel_url.query['revision-number'])
        if playing.revision != revision:
            # Not a valid response as a real device, just to make tests fail
            return web.Response(status=500)

        if playing.paused is not None:
            body += tags.uint32_tag('caps', 3 if playing.paused else 4)

        if playing.title is not None:
            body += tags.string_tag('cann', playing.title)

        if playing.artist is not None:
            body += tags.string_tag('cana', playing.artist)

        if playing.album is not None:
            body += tags.string_tag('canl', playing.album)

        if playing.genre is not None:
            body += tags.string_tag('cang', playing.genre)

        if playing.total_time is not None:
            total_time = playing.total_time * 1000  # sec -> ms
            body += tags.uint32_tag('cast', total_time)

            if playing.position is not None:
                pos = (playing.total_time - playing.position)

return web.Response(status=500)

        if playing.paused is not None:
            body += tags.uint32_tag('caps', 3 if playing.paused else 4)

        if playing.title is not None:
            body += tags.string_tag('cann', playing.title)

        if playing.artist is not None:
            body += tags.string_tag('cana', playing.artist)

        if playing.album is not None:
            body += tags.string_tag('canl', playing.album)

        if playing.genre is not None:
            body += tags.string_tag('cang', playing.genre)

        if playing.total_time is not None:
            total_time = playing.total_time * 1000  # sec -> ms
            body += tags.uint32_tag('cast', total_time)

            if playing.position is not None:
                pos = (playing.total_time - playing.position)
                body += tags.uint32_tag('cant', pos*1000)  # sec -> ms

        if playing.mediakind is not None:
            body += tags.uint32_tag('cmmk', playing.mediakind)

        if playing.playstatus is not None:
            body += tags.uint32_tag('caps', playing.playstatus)

        if playing.repeat is not None:

playing = self._get_response('playing')

        # Make sure revision matches
        revision = int(request.rel_url.query['revision-number'])
        if playing.revision != revision:
            # Not a valid response as a real device, just to make tests fail
            return web.Response(status=500)

        if playing.paused is not None:
            body += tags.uint32_tag('caps', 3 if playing.paused else 4)

        if playing.title is not None:
            body += tags.string_tag('cann', playing.title)

        if playing.artist is not None:
            body += tags.string_tag('cana', playing.artist)

        if playing.album is not None:
            body += tags.string_tag('canl', playing.album)

        if playing.genre is not None:
            body += tags.string_tag('cang', playing.genre)

        if playing.total_time is not None:
            total_time = playing.total_time * 1000  # sec -> ms
            body += tags.uint32_tag('cast', total_time)

            if playing.position is not None:
                pos = (playing.total_time - playing.position)
                body += tags.uint32_tag('cant', pos*1000)  # sec -> ms

        if playing.mediakind is not None:

async def handle_request(self, request):
        """Respond to request if PIN is correct."""
        service_name = request.rel_url.query['servicename']
        received_code = request.rel_url.query['pairingcode'].lower()
        _LOGGER.info('Got pairing request from %s with code %s',
                     service_name, received_code)

        if self._verify_pin(received_code):
            cmpg = tags.uint64_tag('cmpg', int(self._pairing_guid, 16))
            cmnm = tags.string_tag('cmnm', self._name)
            cmty = tags.string_tag('cmty', 'iPhone')
            response = tags.container_tag('cmpa', cmpg + cmnm + cmty)
            self._has_paired = True
            self.service.credentials = '0x' + self._pairing_guid
            return web.Response(body=response)

        # Code did not match, generate an error
        return web.Response(status=500)

def _move(direction, time, point1, point2):
        data = 'touch{0}&time={1}&point={2},{3}'.format(
            direction, time, point1, point2)
        return tags.uint8_tag('cmcc', 0x30) + tags.string_tag('cmbe', data)

async def handle_request(self, request):
        """Respond to request if PIN is correct."""
        service_name = request.rel_url.query['servicename']
        received_code = request.rel_url.query['pairingcode'].lower()
        _LOGGER.info('Got pairing request from %s with code %s',
                     service_name, received_code)

        if self._verify_pin(received_code):
            cmpg = tags.uint64_tag('cmpg', int(self._pairing_guid, 16))
            cmnm = tags.string_tag('cmnm', self._name)
            cmty = tags.string_tag('cmty', 'iPhone')
            response = tags.container_tag('cmpa', cmpg + cmnm + cmty)
            self._has_paired = True
            self.service.credentials = '0x' + self._pairing_guid
            return web.Response(body=response)

        # Code did not match, generate an error
        return web.Response(status=500)