    @Test
    public void testGetFirstHeader_caseInsensitive() throws Exception {

        assertEquals("testCustomEvent", subject.getFirstHeader(ResponseHeader.CUSTOM_EVENT_NAME));
        assertEquals("http://example.com/", subject.getFirstHeader(ResponseHeader.CLICK_TRACKING_URL));
        assertEquals("http://mopub.com/", subject.getFirstHeader(ResponseHeader.FAIL_URL));
        assertNull(subject.getFirstHeader(ResponseHeader.CUSTOM_EVENT_DATA));
    }