GtkTreeModel *gtk_tree_model_sort_get_model (GtkTreeModelSort *tree_model);
GtkTreePath *gtk_tree_model_sort_convert_child_path_to_path (GtkTreeModelSort *tree_model_sort,
GtkTreePath *child_path);
-void gtk_tree_model_sort_convert_child_iter_to_iter (GtkTreeModelSort *tree_model_sort,
+gboolean gtk_tree_model_sort_convert_child_iter_to_iter (GtkTreeModelSort *tree_model_sort,
GtkTreeIter *sort_iter,
GtkTreeIter *child_iter);
GtkTreePath *gtk_tree_model_sort_convert_path_to_child_path (GtkTreeModelSort *tree_model_sort,