Gtk.TreeModelSort.prototype.reset_default_sort_func

function reset_default_sort_func():void {
    // Gjs wrapper for gtk_tree_model_sort_reset_default_sort_func()
}

This resets the default sort function to be in the 'unsorted' state. That is, it is in the same order as the child model. It will re-sort the model to be in the same order as the child model only if the Gtk.TreeModelSort is in 'unsorted' state.