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
return null;
    }
    
    protected Object[] getRawChildren(Object parent) {
        if (parent != null) {
            if (equals(parent, getRoot()))
                return super.getRawChildren(parent);
            ITreeContentProvider cp = (ITreeContentProvider) getContentProvider();
            if (cp != null) {
                Object[] result = cp.getChildren(parent);
                if (result != null)
                    return result;
            }
        }
        return new Object[0];
    }
    /**
     * Returns all selected items for the given SWT control.
     * 
     * @param control
     *           the control
     * @return the list of selected items
     */
    protected abstract Item[] getSelection(Control control);
    
    protected List getSelectionFromWidget() {
        Widget[] items = getSelection(getControl());
        ArrayList list = new ArrayList(items.length);
        for (int i = 0; i < items.length; i++) {
            Widget item = items[i];