Gtk.TreeSortable.prototype.get_sort_column_id

function get_sort_column_id():Boolean {
    // Gjs wrapper for gtk_tree_sortable_get_sort_column_id()
}

Fills in sort_column_id and order with the current sort column and the order. It returns true unless the sort_column_id is %GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID or %GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID.