@Test
 public void expires() {
   Calendar calendar = new GregorianCalendar(2008, 11, 18, 11, 20);
   calendar.setTimeZone(TimeZone.getTimeZone("CET"));
   long date = calendar.getTimeInMillis();
   headers.setExpires(date);
   assertEquals("Invalid Expires header", date, headers.getExpires());
   assertEquals(
       "Invalid Expires header", "Thu, 18 Dec 2008 10:20:00 GMT", headers.getFirst("expires"));
 }
 @Test
 public void expiresInvalidDate() {
   headers.set("Expires", "-1");
   assertEquals(-1, headers.getExpires());
 }
 @Test // SPR-10648 (example is from INT-3063)
 public void expiresInvalidDate() {
   headers.set("Expires", "-1");
   assertEquals(-1, headers.getExpires());
 }