/** Two objects that are equal are required to return the same hashCode. */
 public void testHashCode() {
   QuarterDateFormat qf1 =
       new QuarterDateFormat(TimeZone.getTimeZone("GMT"), new String[] {"1", "2", "3", "4"});
   QuarterDateFormat qf2 =
       new QuarterDateFormat(TimeZone.getTimeZone("GMT"), new String[] {"1", "2", "3", "4"});
   assertTrue(qf1.equals(qf2));
   int h1 = qf1.hashCode();
   int h2 = qf2.hashCode();
   assertEquals(h1, h2);
 }