docs: def avatar_url_from_email(email, size=64, default='retro', dns=False):
      """
      Our own implementation since fas doesn't support this nicely yet.
      """
  
      if dns:
          # This makes an extra DNS SRV query, which can slow down our webapps.
          # It is necessary for libravatar federation, though.
          import libravatar
          return libravatar.libravatar_url(
              email=email,
              size=size,
              default=default,
          )
      else:
          params = _ordered_query_params([('s', size), ('d', default)])
          query = parse.urlencode(params)
          hash = md5(email.encode('utf-8')).hexdigest()
          return "https://seccdn.libravatar.org/avatar/%s?%s" % (hash, query)