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/StructuredViewer.java
* @param element
	 *            the element to reveal
	 */
	public abstract void reveal(Object element);
	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.viewers.ContentViewer#setContentProvider(org.eclipse.jface.viewers.IContentProvider)
	 */
	public void setContentProvider(IContentProvider provider) {
		assertContentProviderType(provider);
		super.setContentProvider(provider);
	}
	/**
	 * Assert that the content provider is of one of the
	 * supported types.
	 * @param provider
	 */
	protected void assertContentProviderType(IContentProvider provider) {
		Assert.isTrue(provider instanceof IStructuredContentProvider);
	}
	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.viewers.Viewer#setInput(java.lang.Object)
	 */
	public final void setInput(Object input) {
		try {
			
			unmapAllElements();
			super.setInput(input);
		} finally {