docs: def parse_MML(self, mml):
          ''' parse the MML structure '''
          hashes_c = []
          mentions_c = []
          soup = BeautifulSoup(mml, "lxml")
          hashes = soup.find_all('hash', {"tag": True})
          for hashe in hashes:
              hashes_c.append(hashe['tag'])
          mentions = soup.find_all('mention', {"uid": True})
          for mention in mentions:
              mentions_c.append(mention['uid'])
          msg_string = soup.messageml.text.strip()
          self.logger.debug('%s : %s : %s' % (hashes_c, mentions_c, msg_string))
          return hashes_c, mentions_c, msg_string