public static void dump(Composite parent, String comment) {
    System.out.println(comment);
    int i = 1;
    System.out.println("parent=" + parent.hashCode());
    check(parent);

    Composite p = parent.getParent();
    while (p != null) {
      check(p);
      p = p.getParent();
      ++i;
    }
    dump(parent, 0);
  }