private static boolean checkPathIsOutsideOfFragment(int def, int ref, Instruction[] flow, LinkedHashSet<Integer> fragmentInsns) {
    Boolean path = findPath(flow[def], ref, fragmentInsns, false, new HashMap<>());
    assert path != null : "def=" + def + ", ref=" + ref;
    return path.booleanValue();
  }
private static boolean checkPathIsOutsideOfFragment(int def, int ref, Instruction[] flow, LinkedHashSet<Integer> fragmentInsns)