Bug 127861 [DataBinding] Mark API provisional
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/viewers/UpdatableTreeContentProvider.java
/**
         * Adds child elements. Must be called from the UI thread.
         * 
         * @param added
         *            elements to add
         */
        private void doAdd(Collection added) {
            if (added.isEmpty()) {
                return;
            }
            for (Iterator iter = added.iterator(); iter.hasNext();) {
				Object object = iter.next();
				
                createSubtree(this.node, object, false);
            }
            if (mapElementToValueTreeNode.containsKey(node)) {
                treeViewer.add(node, added.toArray());
            }
            doFireAdd(added);
        }
        private void doRemove(Collection removed) {
            if (removed.isEmpty()) {
                return;
            }
            Collection actuallyRemoved = new ArrayList();
            
            for (Iterator iter = removed.iterator(); iter.hasNext();) {
				Object object = iter.next();
				
                if (pruneSubtree(node, object)) {