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
}
    
    protected Widget doFindItem(Object element) {
        
        Object root = getRoot();
        if (root == null)
            return null;
        Item[] items = getChildren(getControl());
        if (items != null) {
            for (int i = 0; i < items.length; i++) {
                Widget o = internalFindItem(items[i], element);
                if (o != null)
                    return o;
            }
        }
        return null;
    }
    /**
     * Copies the attributes of the given element into the given SWT item.
     * 
     * @param item
     *           the SWT item
     * @param element
     *           the element
     */
    protected abstract void doUpdateItem(Item item, Object element);
    
    protected void doUpdateItem(Widget widget, Object element, boolean fullMap) {
        if (widget instanceof Item) {
            Item item = (Item) widget;