@Test
public void shouldParseDateHeader() {

    Headers customHeaders = new Headers();
    customHeaders.setHeader("If-Modified-Since", "Thu, 15 Jan 2015 16:30:13 GMT");
    customHeaders.setHeader("If-Modified-Since-MALFORMED", "Malformed Value");
    httpServletRequestImpl = builder.withHeaders(customHeaders).build();
    assertThat(httpServletRequestImpl.getDateHeader("If-Modified-Since"), is(1421339413000L));
    assertThat(httpServletRequestImpl.getDateHeader("If-Modified-Since-MALFORMED"), is(-1L));
    assertThat(httpServletRequestImpl.getDateHeader("Inexisting"), is(-1L));
}