@Test
 public void testContains() {
   fem.persist(entity);
   fem.persist(entity2);
   assertTrue(fem.contains(entity));
   assertTrue(fem.contains(entity2));
 }
 @Test
 public void testRemove() {
   fem.persist(entity);
   fem.persist(entity2);
   fem.contains(entity);
   fem.contains(entity2);
   fem.remove(entity2);
   assertFalse(fem.contains(entity2));
 }