Fix example to match new usage of dtkWidgetsLayoutWriter / Reader.
requested to merge 47-one-should-be-able-to-write-more-specifically-into-the-node-in-an-inheriting-class-of into develop
Prochaines maintenances programmées: lundi 06/05, lundi 03/06, lundi 01/07
Pour plus d'informations: https://doc-si.inria.fr/display/SU/Gitlab