code: def build_avatar_url(jid):
          
          digest = md5(str(jid).encode("utf-8")).hexdigest()
          return "http://www.gravatar.com/avatar/{md5}?d=monsterid".format(md5=digest)
docs: Static method to build a gravatar url with the agent's JID
  
          Args:
            jid (aioxmpp.JID): an XMPP identifier
  
          Returns:
            str: an URL for the gravatar