public DescriptiveUrl find(DescriptiveUrl.Type type) {
        for(DescriptiveUrl url : this) {
            if(url.getType().equals(type)) {
                return url;
            }
        }
        return DescriptiveUrl.EMPTY;
    }
@Test
    public void testFind() {
        final DescriptiveUrlBag list = new DescriptiveUrlBag();
        final DescriptiveUrl url = new DescriptiveUrl(URI.create("http://example.net"));
        list.add(url);
        assertEquals(DescriptiveUrl.EMPTY, list.find(DescriptiveUrl.Type.provider));
        assertEquals(url, list.find(DescriptiveUrl.Type.http));
    }