@Test
  public void testSetRenderRunnable() {
    WidgetAdapterImpl adapter = new WidgetAdapterImpl("id");
    IRenderRunnable runnable = mock(IRenderRunnable.class);

    adapter.setRenderRunnable(runnable);

    assertSame(runnable, adapter.getRenderRunnable());
  }
  @Test
  public void testNonSerializableFields() throws Exception {
    String property = "foo";
    WidgetAdapterImpl adapter = new WidgetAdapterImpl("id");
    adapter.setCachedVariant("cachedVariant");
    adapter.setRenderRunnable(mock(IRenderRunnable.class));
    adapter.preserve(property, "bar");

    WidgetAdapterImpl deserializedAdapter = Fixture.serializeAndDeserialize(adapter);

    assertNull(deserializedAdapter.getCachedVariant());
    assertNull(deserializedAdapter.getRenderRunnable());
    assertNull(deserializedAdapter.getPreserved(property));
  }