Bug 128298 ViewerSorter.compare() does not need to be overridden from superclass
The ViewerComparator class was added as a superclass of ViewerSorter (for ICU4J). ViewerSorter overrides compare() from ViewerComparator, but this is not necessary if in the superclass implementation getComparator().compare() is called, instead of comparator.compare().
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ViewerComparator.java
* </p>
 * <p>
 * Subclasses may implement the <code>isSorterProperty</code> method;
 * they may reimplement the <code>category</code> method to provide 
 * categorization; and they may override the <code>compare</code> methods
 * to provide a totally different way of sorting elements.
 * </p>
 * @see IStructuredContentProvider
 * @see StructuredViewer
 * 
 * @since 3.2
 */
public class ViewerComparator {
	/**
	 * The comparator to use to sort a viewer's contents.
	 */
	private Comparator comparator;
	/**
     * Creates a new {@link ViewerComparator}, which uses the default comparator
     * to sort strings.
	 *
	 */
	public ViewerComparator(){
		this(Policy.getComparator());
	}
	
	/**
     * Creates a new {@link ViewerComparator}, which uses the given comparator
     * to sort strings.
     *