Bug 75711 AstProvider should not create AST if requested by SelectionListenerWithASTManager
3.1 M2 If SelectionListenerWithASTManager waits for an AST and the editor closes we should not create an AST for that one but return null instead.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/FindOccurrencesEngine.java
view.searchFinished();
	}
	private Object getGroupByKey(IMarker marker) {
		try {
			return marker.getAttribute(IMarker.LINE_NUMBER);
		} catch (CoreException e) {
		}
		return marker;
	}
	
	private void run(final IWorkspaceRunnable runnable) {
		BusyIndicator.showWhile(null,
			new Runnable() {
				public void run() {
					try {
						JavaCore.run(runnable, null);
					} catch (CoreException e) {
						JavaPlugin.log(e);
					}
				}
			}
		);
	}
	
	private void performNewSearch(IOccurrencesFinder finder, IDocument document, IJavaElement element) {
		NewSearchUI.activateSearchResultView();
		NewSearchUI.runQuery(new OccurrencesSearchQuery(finder, document, element));
	}
}