@Test
public void testSuccess() {

    ServiceAccountProvider provider = new ServiceAccountProvider();
    KerberosUserMapper mapper = new KerberosUserMapper();
    AccessToken accessToken = provider.getAccessToken(mapper.map("alice@EXAMPLE.COM"), SCOPES);
    assertTrue(accessToken.getValue().startsWith("y"));
    assertEquals(2, CharMatcher.is('.').countIn(accessToken.getValue()));
    assertTrue(accessToken.getExpiresAt() > 0);
}