void () { registerDomExtender(MyCustomChildrenElement.class, ModestDomExtender.class); final MyCustomChildrenElement myElement = createElement("<a><concrete-child/><concrete-child/></a>", MyCustomChildrenElement.class); final List<MyConcreteElement> list = myElement.getConcreteChildren(); final List<MyConcreteElement> list2 = myElement.getConcreteChildren(); assertSame(list.get(0), list2.get(0)); assertSame(list.get(1), list2.get(1)); }