Bug 294303 [Markers] 'Queuing Viewer Updates' in Problems view
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
private static final String TAG_PART_NAME = "partName"; 
	private static final String TAG_COLUMN_WIDTHS = "columnWidths"; 
	private MarkerContentGenerator generator;
	private CachedMarkerBuilder builder;
	private Collection categoriesToExpand;
	private MarkersTreeViewer viewer;
	private ISelectionListener pageSelectionListener;
	private IPartListener2 partListener;
	private Clipboard clipboard;
	
	private IMemento memento;
	private String[] defaultGeneratorIds = new String[0];
	/**
	 * Return a new instance of the receiver.
	 * 
	 * @param contentGeneratorId
	 *            the id of the generator to load.
	 */
	public ExtendedMarkersView(String contentGeneratorId) {
		super();
		defaultGeneratorIds = new String[] { contentGeneratorId };
	}
	/**
	 * Create a preference listener for any preference updates.
	 */ 
	
	
	/**
	 * Add all concrete {@link MarkerSupportItem} elements associated with the
	 * receiver to allMarkers.