Bug 126658 [CommonNavigator] [DND] Complete definition of DND API
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonViewer.java
super.setSorter(new DelegateTreeViewerSorter(sorter));
	}
	/**
	 * <p>
	 * The {@link INavigatorContentService}provides the hook into the framework
	 * to provide content from the various extensions.
	 * </p>
	 * 
	 * @return The {@link INavigatorContentService}that was created when the
	 *         viewer was created.
	 */
	public INavigatorContentService getNavigatorContentService() {
		return contentService;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.AbstractTreeViewer#add(java.lang.Object,
	 *      java.lang.Object[])
	 */
	public void add(Object parentElement, Object[] childElements) {
		
		super.add(parentElement, childElements);
	}
	/**
	 * <p>
	 * Removals are handled by refreshing the parents of each of the given
	 * elements. The parents are determined via calls ot the contentProvider.
	 * </p>
	 *