@Test
public void testWalkObjectGraphNullReference() throws Exception {

	NullReference nullReference = new NullReference();
	ObjectGraphUtil.walkObjectGraph(nullReference, _recordVisitor);
	Assert.assertEquals(_entries.toString(), 1, _entries.size());
	Map.Entry<Field, Object> entry = _entries.get(0);
	Assert.assertEquals(
		ReflectionUtil.getDeclaredField(NullReference.class, "_object"),
		entry.getKey());
	Assert.assertSame(nullReference, entry.getValue());
}