code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.LinkedList;
  
  /*
   * Copyright 1999 Sun Microsystems, Inc.  All Rights Reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
   * CA 95054 USA or visit www.sun.com if you need additional information or
   * have any questions.
   */
  
  /*
   * @test
   * @bug     4216997
   * @summary Cloning a subclass of LinkedList results in an object that isn't
   *          an instance of the subclass.  The same applies to TreeSet and
   *          TreeMap.
   */
  
  import java.util.*;
  
  public class Clone {
      public static void main(String[] args) {
          LinkedList2 l = new LinkedList2();
          LinkedList2 lClone = (LinkedList2) l.clone();
          if (!(l.equals(lClone) && lClone.equals(l)))
              throw new RuntimeException("LinkedList.clone() is broken 1.");
          l.add("a");
          lClone = (LinkedList2) l.clone();
          if (!(l.equals(lClone) && lClone.equals(l)))
              throw new RuntimeException("LinkedList.clone() is broken 2.");
          l.add("b");
          lClone = (LinkedList2) l.clone();
          if (!(l.equals(lClone) && lClone.equals(l)))
              throw new RuntimeException("LinkedList.clone() is broken 2.");
  
  
          TreeSet2 s = new TreeSet2();
          TreeSet2 sClone = (TreeSet2) s.clone();
          if (!(s.equals(sClone) && sClone.equals(s)))
              throw new RuntimeException("TreeSet.clone() is broken.");
          s.add("a");
          sClone = (TreeSet2) s.clone();
          if (!(s.equals(sClone) && sClone.equals(s)))
              throw new RuntimeException("TreeSet.clone() is broken.");
          s.add("b");
          sClone = (TreeSet2) s.clone();
          if (!(s.equals(sClone) && sClone.equals(s)))
              throw new RuntimeException("TreeSet.clone() is broken.");
  
          TreeMap2 m = new TreeMap2();
          TreeMap2 mClone = (TreeMap2) m.clone();
          if (!(m.equals(mClone) && mClone.equals(m)))
              throw new RuntimeException("TreeMap.clone() is broken.");
          m.put("a", "b");
          mClone = (TreeMap2) m.clone();
          if (!(m.equals(mClone) && mClone.equals(m)))
              throw new RuntimeException("TreeMap.clone() is broken.");
          m.put("c", "d");
          mClone = (TreeMap2) m.clone();
          if (!(m.equals(mClone) && mClone.equals(m)))
              throw new RuntimeException("TreeMap.clone() is broken.");
      }
  
      private static class LinkedList2 extends LinkedList {};
      private static class TreeSet2    extends TreeSet {};
      private static class TreeMap2    extends TreeMap {};
  }
  