@Test(expected = TechnicalException.class)
    public void testCallbackMandatory() {
        Client localClient = new GaeUserServiceClient();
        localClient.getRedirectionAction(new CallContext(context, new MockSessionStore()));
    }
Tests the {@link GaeUserServiceClient}.

@author Jerome Leleu
@since 1.9.0
pac4j-gae/src/test/java/org/pac4j/gae/client/GaeUserServiceClientTests.java