gtk_tree_store_append(tree_store, &iter, NULL);
gtk_tree_store_set(tree_store, &iter, 0, st->service_type, 1, "", 2, NULL, -1);
gtk_tree_store_append(tree_store, &iter, NULL);
gtk_tree_store_set(tree_store, &iter, 0, st->service_type, 1, "", 2, NULL, -1);