Bug 65762 [Viewers] Need to back out of change to AbstractTreeViewer.isExpandable
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
}
	/**
	 * Collapses 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 collapse
	 *           all levels of the tree
	 */
	public void collapseToLevel(Object element, int level) {
		Assert.isNotNull(element);
		Widget w = findItem(element);
		if (w != null)
			internalCollapseToLevel(w, level);
	}
	/**
	 * Creates all children for the given widget.
	 * <p>
	 * The default implementation of this framework method assumes that <code>widget.getData()</code>
	 * returns the element corresponding to the node. Note: the node is not
	 * visually expanded! You may have to call <code>parent.setExpanded(true)</code>.
	 * </p>
	 * 
	 * @param widget
	 *           the widget
	 */
	protected void createChildren(final Widget widget) {
		final Item[] tis = getChildren(widget);
		if (tis != null && tis.length > 0) {