AtomDate implements Cloneable, Serializable { @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + value.hashCode(); return result; } AtomDate();  AtomDate(String value);  AtomDate(Date value);  AtomDate(Calendar value);  AtomDate(long value); String getValue(); AtomDate setValue(String value); AtomDate setValue(Date date); AtomDate setValue(Calendar calendar); AtomDate setValue(long timestamp); Date getDate(); Calendar getCalendar(); long getTime(); @Override String toString(); @Override int hashCode(); @Override boolean equals(Object obj); @Override Object clone(); static Date parse(String date); static String format(Date date); static AtomDate valueOf(String value); static AtomDate valueOf(Date value); static AtomDate valueOf(Calendar value); static AtomDate valueOf(long value);  }
@Test public void testHashCode() { long time = System.currentTimeMillis(); AtomDate ad1 = new AtomDate(time); assertTrue(ad1.hashCode() == ad1.hashCode()); AtomDate ad2 = new AtomDate(time + 10); assertFalse(ad1.hashCode() == ad2.hashCode()); }