@Test
 public void serviceReturnsDigest() throws Exception {
   String digest = LocalDigestValidator.SHA(SHARED_SECRET + TICKET, ENCODING, HASH_FUNCTION);
   String result = client.validateDigest(digest, TICKET, "myserviceurl", USER);
   String responsedigest =
       LocalDigestValidator.SHA(SHARED_SECRET + TICKET + USER, ENCODING, HASH_FUNCTION);
   assertEquals(responsedigest, result);
 }
 @Test(expected = InvalidDigestException.class)
 public void serviceReturnsError() throws Exception {
   client.validateDigest("BAD_DIGEST", TICKET, "myserviceurl", USER);
 }
 @Before
 public void setUp() {
   client.setHttpClient(new HttpClientMock());
 }