### Question:
YandexSearcher extends AbstractSearcher<WebContent> { void checkSearchUrlValidity(String yandexSearchUrl) { if (yandexSearchUrl == null || yandexSearchUrl.isEmpty()) { throw new IllegalArgumentException("Search URL must be supplied."); } if (!yandexSearchUrl.matches(SEARCH_URL_PATTERN)) { throw new IllegalArgumentException( "The supplied search URL is invalid. It must start with \"http: } } YandexSearcher(String yandexSearchUrl);  YandexSearcher(Configuration configuration);   YandexSearcher(); @Override String getName(); @Override List<WebContent> search(String query, int resultCount, Language language); static int getRequestCount(); static final String CONFIG_SEARCH_URL; }### Answer:
@Test public void testCheckSearchUrlValidity() { yandexSearcher .checkSearchUrlValidity("http: try { yandexSearcher.checkSearchUrlValidity("http: fail(); } catch (IllegalArgumentException e) { } try { yandexSearcher.checkSearchUrlValidity(""); fail(); } catch (IllegalArgumentException e) { } try { yandexSearcher.checkSearchUrlValidity(null); fail(); } catch (IllegalArgumentException e) { } }