Bug 127861 [DataBinding] Mark API provisional
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/viewers/UpdatableTreeContentProvider.java
protected Collection computeElements() {
            return UpdatableTreeContentProvider.this.computeKnownElements();
        }
        public void doFireAdd(Collection added) {
            fireAdded(added);
        }
        public void doFireRemove(Collection removed) {
            fireRemoved(removed);
        }
        
        public void doFireStale(boolean isStale) {
        	fireStale(isStale);
        }
    };
    private KnownElementsSet elements = new KnownElementsSet();
	private Object inputElement;
    private class ValueTreeNode implements IChangeListener {
        private HashSet parents = new HashSet();
        private Object node;
        
        private Object parent;