Bug 305703 [Viewers][CommonNavigator] remembered contributions can leak when using filters
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/StructuredViewerManager.java
private StructuredViewer viewer;
	private Object cachedOldInput;
	private Object cachedNewInput;
	/*
	 * This map is used to associate elements in the viewer with their
	 * associated NavigatorContentDescriptor. To avoid things getting out of
	 * hand, it associates only the items that are actually present in the tree.
	 * We need this association to make sure that we can always get the source
	 * (NavigatorContentDescriptor) of a given element for the case of providing
	 * the label which must use the same navigator content extension that
	 * provided the element.
	 */
	
	private Map viewerDataMap;
	
	static class StructuredViewerAccess extends StructuredViewerInternals {