Initialization of WikiObjectComponentBuilder based wiki components fail when one of the xobject is null

   private void unRegisterObjectComponents(XWikiDocument document)
    {
        for (Map.Entry<DocumentReference, List<BaseObject>> entry : document.getXObjects().entrySet()) {
            WikiObjectComponentBuilder componentBuilder = getAssociatedComponentBuilder(entry.getKey());

            if (componentBuilder != null) {
                for (BaseObject baseObject : entry.getValue()) {
                    if (baseObject != null) {
                        this.wikiObjectComponentManagerEventListenerProxy
                            .unregisterObjectComponents(baseObject.getReference());
                    }
                }
            }
        }
    }