@Test
  public void testAddSerializerForTransientPersistentCombo() throws Exception {
    DefaultSerializationProviderConfiguration config =
        new DefaultSerializationProviderConfiguration();
    config.addSerializerFor(Long.class, ComboSerializer.class);

    assertSame(ComboSerializer.class, config.getPersistentSerializers().get(Long.class));
    assertSame(ComboSerializer.class, config.getTransientSerializers().get(Long.class));
  }
  @Test
  public void testAddSerializerForPersistent() throws Exception {
    DefaultSerializationProviderConfiguration config =
        new DefaultSerializationProviderConfiguration();
    config.addSerializerFor(Long.class, PersistentSerializer.class);

    assertTrue(config.getTransientSerializers().isEmpty());
    assertSame(PersistentSerializer.class, config.getPersistentSerializers().get(Long.class));
  }
 @Test(expected = IllegalArgumentException.class)
 public void testAddSerializerForUnusable() throws Exception {
   DefaultSerializationProviderConfiguration config =
       new DefaultSerializationProviderConfiguration();
   config.addSerializerFor(Long.class, UnusableSerializer.class);
 }