### Question:
AppUtils { public String getReturnUrl(final String url, final String fallback) { if (url == null || url.isBlank()) { return fallback; } try { final URI uri = new URI(url); if (uri.isAbsolute()) { return fallback; } return url; } catch (final URISyntaxException ex) { return fallback; } }  List<String> getModelErrors(final BindingResult bindingResult, final String... excludedFields); void setCurrentPage(final Model model, final String currentPage); @SuppressWarnings("unchecked") void addNotification(final RedirectAttributes redirectAttributes, final Notification notification); List<String> getUnexpectedErrorMessageAsList(); String getUnexpectedErrorMessage(); List<String> getMessages(final String... messageKeys); String getMessage(final String messageKey); String getReturnUrl(final String url, final String fallback); String getLocalUrl(final HttpServletRequest request);  }### Answer:
@Test public void test_getReturnURL_nullURL() { final String result = appUtils.getReturnUrl(null, "fallback"); assertEquals("fallback", result); }
@Test public void test_getReturnURL_blankURL() { final String result = appUtils.getReturnUrl(" ", "fallback"); assertEquals("fallback", result); }
@Test public void test_getReturnURL_invalidURL() { final String result = appUtils.getReturnUrl("http: assertEquals("fallback", result); }
@Test public void test_getReturnURL_absoluteURL() { final String result = appUtils.getReturnUrl("http: assertEquals("fallback", result); }
@Test public void test_getReturnURL_relativeURL() { final String result = appUtils.getReturnUrl("/movie/name", "fallback"); assertEquals("/movie/name", result); }