Bug 181061 [Viewers] JFace viewers performance issues in 3.3
A number of the JFace performance tests are red since I20060926-0800.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
internalSetExpandedTreePaths(expandedTreePaths, getControl(),
				new TreePath(new Object[0]));
	}
	/**
	 * Sets whether the node corresponding to the given element or tree path is
	 * expanded or collapsed.
	 * 
	 * @param elementOrTreePath
	 *            the element
	 * @param expanded
	 *            <code>true</code> if the node is expanded, and
	 *            <code>false</code> if collapsed
	 */
	public void setExpandedState(Object elementOrTreePath, boolean expanded) {
		Assert.isNotNull(elementOrTreePath);
		Widget item = internalExpand(elementOrTreePath, false);
		if (item instanceof Item) {
			if (expanded) {
				createChildren(item);
			}
			setExpanded((Item) item, expanded);
		}
	}
	/**
	 * Sets the selection to the given list of items.
	 * 
	 * @param items
	 *            list of items (element type: