diff --git a/src/ui/sand_box.c b/src/ui/sand_box.c
index b6898c5..e0675b5 100644
--- a/src/ui/sand_box.c
+++ b/src/ui/sand_box.c
@@ -67,9 +67,9 @@ static void on_selection_change (GtkStringList *my_selection_model,  guint posit
     nombre d'éléments ayant changé d'état = %2d\n",
         g_list_model_get_n_items (G_LIST_MODEL (my_selection_model)),
         g_list_model_get_item_type(G_LIST_MODEL (my_selection_model)),
-        position,
-        gtk_string_list_get_string (my_selection_model, position),
-        n_items );
+        position, "debug", 0);
+        /* gtk_string_list_get_string (my_selection_model, position),  //  GTK_STRING_LIST ? */
+        /* n_items ); */
 }
 
 //-------------------------------------------------------------------------------------------------------------------------------------------
@@ -85,8 +85,8 @@ GListModel *my_item_create_func (gpointer item, gpointer user_data)
 
     if (strcmp(gtk_string_object_get_string(item), "zero")) {
         GtkWidget *my_expander = gtk_expander_new (NULL);
-        /* gtk_expander_set_child (GTK_EXPANDER(my_expander), NULL); */
-        /* on_activating_this_expander (GTK_EXPANDER(my_expander), NULL); */
+        gtk_expander_set_child (GTK_EXPANDER(my_expander), NULL);
+        on_activating_this_expander (GTK_EXPANDER(my_expander), NULL);
         return G_LIST_MODEL (my_child_string_list);
     }
     else return NULL;
@@ -105,15 +105,15 @@ static void and_now_let_s_climb_that_tree (GtkWidget *in_that_box)
     GtkListItemFactory *my_list_item_factory = gtk_signal_list_item_factory_new ();
     g_signal_connect (my_list_item_factory, "setup", G_CALLBACK (on_setup_cb), NULL);
     g_signal_connect (my_list_item_factory, "bind", G_CALLBACK (on_bind_cb), NULL);
-    if (1) { g_signal_connect (G_LIST_MODEL (my_string_list), "selection-changed", G_CALLBACK (on_selection_change), NULL);}
+    if (1) { g_signal_connect (my_selection_model, "selection-changed", G_CALLBACK (on_selection_change), NULL);}
 
 
 //  GListModel *(* GtkTreeListModelCreateModelFunc) (GObject* item, gpointer user_data)  //  remplacerait gtk_string_list_new() ?
 //  https://docs.gtk.org/gtk4/callback.TreeListModelCreateModelFunc.html
 //  https://docs.gtk.org/gtk4/method.TreeListRow.set_expanded.html
 
-    GtkTreeListModel *my_tree_list_model = gtk_tree_list_model_new (my_selection_model, 1, 1, my_item_create_func, NULL, NULL);
-    int rank = 0; printf("in : GListModel *item_create_func (gpointer item,...)   (line 80)     (item n°%d is %s)\n",
+    GtkTreeListModel *my_tree_list_model = gtk_tree_list_model_new (G_LIST_MODEL (my_string_list), 1, 0, my_item_create_func, NULL, NULL); // my_string_list   my_selection_model
+    int rank = 1; printf("in : GListModel *item_create_func (gpointer item,...)   (line 80)     (item n°%d is %s)\n",
                       rank, gtk_string_list_get_string (my_string_list, rank));
 
     GtkWidget *my_list_view = gtk_list_view_new (GTK_SELECTION_MODEL (my_selection_model), my_list_item_factory);