}

    @Test
    public void test_responseData_parentUrl() {
        final ResponseData responseData = new ResponseData();

        assertNull(responseData.getParentUrl());
        responseData.setParentUrl("http://example.com/parent");
        assertEquals("http://example.com/parent", responseData.getParentUrl());
    }

    @Test
    public void test_responseData_lastModified() {