Bug 89137 [JFace] - API Review - "temporary" API in AbstractTreeViewer
AbstractTreeViewer contains two methods documented as "temporary" internalRefresh(Widget, Object) internalAdd(Widget, Object, Object [])
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* method is equivalent to <code>expandToLevel(ALL_LEVELS)</code>.
     */
    public void expandAll() {
        expandToLevel(ALL_LEVELS);
    }
    /**
     * Expands the root of the viewer's tree to the given level.
     * 
     * @param level
     *           non-negative level, or <code>ALL_LEVELS</code> to expand all
     *           levels of the tree
     */
    public void expandToLevel(int level) {
        expandToLevel(getRoot(), level);
    }
    /**
     * Expands all ancestors of the given element so that the given element
     * becomes visible in this viewer's tree control, and then expands the
     * subtree rooted at the given element to the given level.
     * 
     * @param element
     *           the element
     * @param level
     *           non-negative level, or <code>ALL_LEVELS</code> to expand all
     *           levels of the tree
     */
    public void expandToLevel(Object element, int level) {
        Widget w = internalExpand(element, true);
        if (w != null)
            internalExpandToLevel(w, level);