@Test public void addDateHeader() { response.addDateHeader("Last-Modified", 1437472800000L); response.addDateHeader("Last-Modified", 1437472801000L); assertEquals("Tue, 21 Jul 2015 10:00:00 GMT", response.getHeaders("Last-Modified").get(0)); assertEquals("Tue, 21 Jul 2015 10:00:01 GMT", response.getHeaders("Last-Modified").get(1)); }