anchor.diff:      JavaSystemIO.setProperty("com.google.dart.sdk", sdkPath);
       DartSdk sdk = DirectoryBasedDartSdk.defaultSdk;
   
  -    AnalysisContext context = AnalysisEngine.instance.createAnalysisContext();
  -    var packageUriResolver = new PackageUriResolver(packageRoots.map((pr) =>
  -          new JavaFile.fromUri(new Uri.file(pr))));
  +    var packageUriResolver =
  +        new PackageUriResolver(packageRoots.map(
  +            (pr) => new JavaFile.fromUri(new Uri.file(pr))).toList());
       context.sourceFactory = new SourceFactory.con2([
         new DartUriResolver(sdk),
         new FileUriResolver(),
  
positive.code:       visited.add(currentFile);
        _visitor(currentFile.compilationUnit, currentFile);
        var visitor = new CrawlerVisitor(currentFile, context);
        currentFile.compilationUnit.accept(visitor);
        visitor.toVisit.forEach((SourceFile todo) {
          if (!toVisit.contains(todo) && !visited.contains(todo)) {
            toVisit.add(todo);
  
negative.code:     var sourceFile = new SourceFile(
          entryPointFile.getAbsolutePath(),
          entryPointImport,
          resolvedUnit.element);
      List<SourceFile> visited = <SourceFile>[];
      List<SourceFile> toVisit = <SourceFile>[sourceFile];
  
  