public void unbreakable(InlineBox box, int n) {
public static void unbreakable(InlineBox box, int n) {
    public void unbreakable(InlineBox box, int n) {        if (box.start_index == -1) {            box.start_index = 0;        }        box.setSubstring(box.start_index, box.start_index + n);        return;    }