Bug 215004 [Markers] New Problems view: 'Group by > Type' broken
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerGroup.java
MarkerGroup markerGroup;
		private boolean showing;
		FieldGroup(MarkerGroup group) {
			markerGroup = group;
		}
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.ui.views.markers.internal.IField#compare(java.lang.Object,
		 *      java.lang.Object)
		 */
		public int compare(Object obj1, Object obj2) {
			MarkerGroupingEntry entry1 = getMapping(((MarkerNode) obj1)
					.getConcreteRepresentative());
			MarkerGroupingEntry entry2 = getMapping(((MarkerNode) obj2)
					.getConcreteRepresentative());
			return entry2.getPriority() - entry1.getPriority();
		}
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.ui.views.markers.internal.IField#getColumnHeaderImage()
		 */
		public Image getColumnHeaderImage() {
			return null;
		}