@Before
  public void setup() throws Exception {
    m_injector = Guice.createInjector(new InMemoryDefaultTestModule());
    m_injector.getInstance(GuiceJpaInitializer.class);
  }
Tests {@link TransactionalLocks} and {@link LockArea} and associated classes.
ambari-server/src/test/java/org/apache/ambari/annotations/LockAreaTest.java