Bug 92344 [call hierarchy] JavaModelException when accessing removed type
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/util/JavaUIHelp.java
private StructuredViewer fViewer;
		private String fContextId;
		private JavaEditor fEditor;
		public JavaUIHelpListener(StructuredViewer viewer, String contextId) {
			fViewer= viewer;
			fContextId= contextId;