@Test
    public void testNullMongoClient() {
        val authenticator = new MongoProfileService(null, FIRSTNAME, MongoServer.PASSWORD_ENCODER);
        TestsHelper.expectException(authenticator::init, TechnicalException.class, "mongoClient cannot be null");
    }
Tests the {@link MongoProfileService}.

@author Jerome Leleu
@since 1.8.0
pac4j-mongo/src/test/java/org/pac4j/mongo/profile/service/MongoProfileServiceIT.java