@Test
public void parsesDateHeader() throws Exception {

    SimpleDateFormat dateFormat = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.US);
    Date date = new Date();
    MultivaluedMap<String, Object> headers = new MultivaluedHashMap<>();
    headers.putSingle(DATE, dateFormat.format(date));
    ResponseImpl response = new ResponseImpl(200, "foo", null, headers);
    assertEquals(dateFormat.format(date), dateFormat.format(response.getDate()));
}