Bug 125272 [Viewers] AbstractTreeViewer needs remove(Object parentElement, Object[] childElements)
There is an add(Object parentElement, Object[] childElements) but no corresponding remove(). Without this method, if you have an element that appears under multiple parents, the only way to get model and viewer in sync after removing the element from just one of its parents is calling refresh().
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
*           a tree viewer listener
     */
    public void addTreeListener(ITreeViewerListener listener) {
        treeListeners.add(listener);
    }
    /**
     * Adds the given SWT tree listener to the given SWT control.
     * 
     * @param control
     *           the SWT control
     * @param listener
     *           the SWT tree listener
     */
    protected abstract void addTreeListener(Control control,
            TreeListener listener);
    
    protected void associate(Object element, Item item) {
        Object data = item.getData();
        if (data != null && data != element && equals(data, element)) {
            
            
            
            unmapElement(data, item);
            item.setData(element);
            mapElement(element, item);
        } else {
            
            super.associate(element, item);
        }
    }