Google App Engine Java: Setup Test Configuration

If you want to test a class which depends on Google App Engine infrastructure, such as data storing functionality with "PersistenceManagerFactory", you should set up LocalServiceTestHelper before testing.
I don't tell you the details very much, but I will show you the minimum test setup in the code below.
This code was enough for me to test my data access object functionality.

package com.dukesoftware.gaej.test;

import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

import com.google.appengine.tools.development.testing.LocalDatastoreServiceTestConfig;
import com.google.appengine.tools.development.testing.LocalServiceTestHelper;

public class GoogleAppEngineTest {
    private static final LocalServiceTestHelper helper =
            new LocalServiceTestHelper(new LocalDatastoreServiceTestConfig());

    @BeforeClass
    public static void setUp() {
        helper.setUp();
    }

    @AfterClass
    public static void tearDown() {
        helper.tearDown();
    }

    @Test
    public void testSomething()
    {
        // test functionality which depends on datastore, etc.
    }
}