anchor.diff:      ok = escalus_connection:send(Conn, Stanza),
       wait_for_success(Username, Conn).
   
  +-spec auth_digest_md5(client(), user_spec()) -> ok.
   auth_digest_md5(Conn, Props) ->
       ok = escalus_connection:send(Conn, escalus_stanza:auth(<<"DIGEST-MD5">>)),
       ChallengeData = get_challenge(Conn, challenge1),
  
positive.code: %% Helpers - actions
  %%--------------------------------------------------------------------
  
  get_challenge(Conn, Descr) ->
      get_challenge(Conn, Descr, true).
  
  
negative.code:             throw({expected_challenge, got, Challenge})
      end.
  
  %% Throws!
  -spec wait_for_success(any(), client()) -> ok.
  wait_for_success(Username, Conn) ->
      AuthReply = escalus_connection:get_stanza(Conn, auth_reply),
      case AuthReply#xmlel.name of
  