anchor.diff:  -spec session() -> #xmlel{}.
   session() ->
       NS = <<"urn:ietf:params:xml:ns:xmpp-session">>,
  -    iq(<<"set">>, #xmlel{name = <<"session">>,
  -                         attrs = [{<<"xmlns">>, NS}]}).
  +    iq(<<"set">>, [#xmlel{name = <<"session">>,
  +                          attrs = [{<<"xmlns">>, NS}]}]).
   
   to(Stanza, Recipient) when is_binary(Recipient) ->
       setattr(Stanza, <<"to">>, Recipient);
  
positive.code: auth(Mechanism) ->
      auth(Mechanism, []).
  
  -spec auth(binary(), #xmlcdata{}) -> #xmlel{}.
  auth(Mechanism, Children) ->
      #xmlel{name = <<"auth">>,
             attrs = [{<<"xmlns">>, ?NS_SASL},
  
negative.code: -spec iq(binary(), [xmlterm()]) -> #xmlel{}.
  iq(Type, Body) ->
      #xmlel{name = <<"iq">>,
             attrs = [{<<"type">>, Type},
                      {<<"id">>, id()}],
             children = Body}.
  
  iq(To, Type, Body) ->
  