Copyright (c) 2000, 2010 IBM Corporation and others.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
which accompanies this distribution, and is available at
IBM Corporation - initial API and implementation
Default sorting order, by label.
if (cat1 != cat2) return cat1 - cat2;
compareResult = super.compare(viewer, o1, o2);
return ascending ? compareResult : -compareResult;
return super.compare(viewer, o1, o2);
if (tag1 == null) return 1;
if (tag2 == null) return -1;