### Question:
UrlHelper { public static String makeFullUrl(String pageUrl, String baseUrl, String linkUrl) { if (linkUrl == null) { throw new NullPointerException("linkUrl must not be null"); } if (baseUrl != null && !baseUrl.endsWith("/")) { baseUrl = baseUrl.concat("/"); } String contextUrl; if (pageUrl != null && baseUrl != null) { contextUrl = makeFullUrl(pageUrl, baseUrl); } else if (pageUrl != null) { contextUrl = pageUrl; } else { contextUrl = baseUrl; } return makeFullUrl(contextUrl, linkUrl); } private  UrlHelper(); static String removeSessionId(String originalUrl); static void makeAbsoluteUrls(Document document); static String getBaseUrl(Document document); static String makeFullUrl(String pageUrl, String baseUrl, String linkUrl); static String makeFullUrl(String contextUrl, String linkUrl); static String getCleanUrl(String url); static String removeAnchors(String url); static String getDomain(String url, boolean includeProtocol, boolean includeSubdomain); static String getDomain(String url, boolean includeProtocol); static String getDomain(String url); static String getCanonicalUrl(String url); static String decodeParameter(String string); static String encodeParameter(String string); static List<String> extractUrls(String text); static boolean isLocalFile(URL url); static String createParameterString(List<Pair<String, String>> parameters); static List<Pair<String, String>> parseParams(String parameterString); static String parseBaseUrl(String url); static boolean isValidUrl(String url); static final Pattern URL_PATTERN; }### Answer:
@Test public void testMakeFullUrl() { assertEquals("http: assertEquals("http: assertEquals("http: assertEquals("http: assertEquals("http: UrlHelper.makeFullUrl("http: assertEquals("http: UrlHelper.makeFullUrl("http: assertEquals("http: UrlHelper.makeFullUrl("http: assertEquals("http: UrlHelper.makeFullUrl("http: assertEquals("http: assertEquals("http: assertEquals("http: assertEquals("http: assertEquals("http: assertEquals("http: UrlHelper.makeFullUrl("http: assertEquals("http: UrlHelper.makeFullUrl("http: assertEquals("http: UrlHelper.makeFullUrl("http: assertEquals("http: UrlHelper.makeFullUrl("/some/file/path.html", "http: assertEquals("mailto:example@example.com", UrlHelper.makeFullUrl("http: assertEquals("http: UrlHelper.makeFullUrl(null, null, "http: try { assertEquals(null, UrlHelper.makeFullUrl(null, "http: assertEquals("", UrlHelper.makeFullUrl("http: assertEquals("", UrlHelper.makeFullUrl(null, null, "/page.html")); fail(); } catch (NullPointerException e) { } }