@Test
public void testServiceAccount() {

    HybridProvider provider = new HybridProvider();
    AccessToken accessToken = provider.getAccessToken("alice-shadow@" + projectId + ".iam.gserviceaccount.com", SCOPES);
    assertTrue(accessToken.getValue().startsWith("y"));
    assertEquals(2, CharMatcher.is('.').countIn(accessToken.getValue()));
    assertTrue(accessToken.getExpiresAt() > 0);
}