fOperationHistroy.undoOperation(op, pm, new QueryAdapter(query));
	public void performUndo(IValidationCheckResultQuery query, IProgressMonitor pm) throws CoreException {		IUndoableOperation op= fOperationHistroy.getUndoOperation(RefactoringCorePlugin.getUndoContext());		if (!(op instanceof UndoableOperation2ChangeAdapter)) 			throw new CoreException(new Status(IStatus.ERROR, RefactoringCorePlugin.getPluginId(),				IStatus.ERROR, "Top most undoable operation doesn't represent a refactoring change", null));		if (query == null)			query= new NullQuery();		fOperationHistroy.undoOperation(op, pm, new QueryAdapter(query));	}