'Return the media blob for the msgid.'

@asyncio.coroutine
def async_get_media(self, msgid):

    if (msgid not in self._messages):
        raise StreamError('Message    not    found')
    audio_path = os.path.join(os.path.dirname(__file__), '..', 'tts', 'demo.mp3')
    with open(audio_path, 'rb') as file:
        return file.read()
