anchor.diff:  
       // Update incoming references to this file
       List<SearchMatch> matches =
  -        await workspace.searchEngine.searchReferences(element);
  +        await refactoringWorkspace.searchEngine.searchReferences(element);
       List<SourceReference> references = getSourceReferences(matches);
       for (SourceReference reference in references) {
         await changeBuilder.addFileEdit(reference.file, (builder) {
  
positive.code: 
    final packagePrefixedStringPattern = new RegExp(r'''^r?['"]+package:''');
  
    MoveFileRefactoringImpl(ResourceProvider resourceProvider, this.workspace,
        this.source, this.oldFile)
        : resourceProvider = resourceProvider,
          pathContext = resourceProvider.pathContext {
      if (source != null) {
  
negative.code: 
    @override
    Future<RefactoringStatus> checkFinalConditions() async {
      final drivers = refactoringWorkspace.driversContaining(oldFile);
      if (drivers.length != 1) {
        if (refactoringWorkspace.drivers
            .any((d) => pathContext.equals(d.contextRoot.root, oldFile))) {
          return new RefactoringStatus.fatal(
              'Renaming an analysis root is not supported ($oldFile)');
  