Bug 287103 [CommonNavigator] contentServiceLabelProvider doesn't properly implement overrides
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/ContributorTrackingSet.java
private static final long serialVersionUID = 2516241537206281972L;
	
	private NavigatorContentDescriptor contributor;
	private NavigatorContentService contentService;
	
	/**
	 * Construct a tracking set.
	 * 
	 * @param aContentService 
	 */
	public ContributorTrackingSet(NavigatorContentService aContentService) {
		contentService = aContentService;
	}
	
	/**
	 * Construct a tracking set.