Container need to be ordered?

Vaadin 6 / 7 / 8 Framework Data Binding
1

Following code In Table.refreshRenderedCells needs container to be ordered (or indexed) :

 
           // Gets the first item id
            if (items instanceof Container.Indexed) {
                id = ((Container.Indexed) items).getIdByIndex(firstIndex);
            } else {
                id = ((Container.Ordered) items).firstItemId();
                for (int i = 0; i < firstIndex; i++) {
                    id = ((Container.Ordered) items).nextItemId(id);
                }
            }

But Container documentation says:

2

Well yes, that holds with Containers generally, but some components that accept a Container as data source might have more strict requirements. Actually, you can still put any Container to a Table even if the container is not ordered, because if it is not ordered, setContainerDataSource() automatically wraps it with ContainerOrderedWrapper class.

So there won’t be any class cast exceptions at least, but I’m not exactly sure how sanely the Table will behave if the wrapped non-ordered container gives items out in no particular order.