code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.AbstractMap;
  
  /*
   * Copyright 2005 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 4904074 6328220 6330389
   * @summary Basic tests for SimpleEntry, SimpleImmutableEntry
   * @author Martin Buchholz
   */
  
  import java.util.*;
  import java.util.concurrent.*;
  import static java.util.AbstractMap.*;
  
  public class SimpleEntries {
      private static String k = "foo";
      private static Long v = 1L;
      private static Long v2 = 2L;
      private static void realMain(String[] args) throws Throwable {
          testEntry(new SimpleEntry<String,Long>(k,v));
          testEntry(new SimpleImmutableEntry<String,Long>(k,v));
          testNullEntry(new SimpleEntry<String,Long>(null,null));
          testNullEntry(new SimpleImmutableEntry<String,Long>(null,null));
      }
  
      private static void testEntry(Map.Entry<String,Long> e) {
          equal(e.getKey(), k);
          equal(e.getValue(), v);
          equal(e, new SimpleEntry<String,Long>(k,v));
          check(! e.equals(new SimpleEntry<String,Long>(k,v2)));
          check(! e.equals(null));
          equal(e, new SimpleImmutableEntry<String,Long>(k,v));
          equal(e.toString(), k+"="+v);
          if (e instanceof SimpleEntry) {
              equal(e.setValue(v2), v);
              equal(e.getValue(), v2);
              equal(e.setValue(null), v2);
              equal(e.getValue(), null);
          } else {
              try { e.setValue(v2); fail(); }
              catch (UnsupportedOperationException t) {}
              catch (Throwable t) { unexpected(t); }
          }
      }
  
      private static void testNullEntry(Map.Entry<String,Long> e) {
          equal(e.getKey(), null);
          equal(e.getValue(), null);
          equal(e, new SimpleEntry<String,Long>(null, null));
          equal(e, new SimpleImmutableEntry<String,Long>(null, null));
          equal(e.toString(), "null=null");
          if (e instanceof SimpleEntry) {
              equal(e.setValue(v), null);
              equal(e.getValue(), v);
          } else {
              try { e.setValue(null); fail(); }
              catch (UnsupportedOperationException t) {}
              catch (Throwable t) { unexpected(t); }
          }
      }
  
      //--------------------- Infrastructure ---------------------------
      static volatile int passed = 0, failed = 0;
      static void pass() {passed++;}
      static void fail() {failed++; Thread.dumpStack();}
      static void fail(String msg) {System.out.println(msg); fail();}
      static void unexpected(Throwable t) {failed++; t.printStackTrace();}
      static void check(boolean cond) {if (cond) pass(); else fail();}
      static void equal(Object x, Object y) {
          if (x == null ? y == null : x.equals(y)) pass();
          else fail(x + " not equal to " + y);}
      public static void main(String[] args) throws Throwable {
          try {realMain(args);} catch (Throwable t) {unexpected(t);}
          System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
          if (failed > 0) throw new AssertionError("Some tests failed");}
  }
  