ICompilationUnit cu= null; if (editor != null) {
if (editor instanceof CompilationUnitEditor) {
	public void update() {		ITextEditor editor= getTextEditor();		boolean checked= (editor != null && editor.showsHighlightRangeOnly());		setChecked(checked);		ICompilationUnit cu= null;		if (editor != null) {			IWorkingCopyManager manager= JavaPlugin.getDefault().getWorkingCopyManager();			cu= manager.getWorkingCopy(editor.getEditorInput());		}		setEnabled(cu != null);	}