anchor.diff:  
     Stream<List<int>> load(String pathToLoad) {
       return futureStream(new Future.value().then((_) {
  -      if (_path.isAbsolute(pathToLoad)) {
  +      if (path.posix.isAbsolute(pathToLoad)) {
           throw new ArgumentError("Can't load absolute path '$pathToLoad'.");
         }
   
  -      var split = _path.split(_path.normalize(pathToLoad));
  +      var split = path.posix.split(path.posix.normalize(pathToLoad));
         if (split.isEmpty || split.first == '.' || split.first == '..') {
           throw new ArgumentError("Can't load '$pathToLoad' from within "
               "'$name'.");
  
positive.code: import '../../descriptor.dart';
  import '../../scheduled_test.dart';
  import '../utils.dart';
  
  /// A path builder to ensure that [load] uses POSIX paths.
  final path.Builder _path = new path.Builder(style: path.Style.posix);
  
  /// A descriptor describing a directory containing multiple files.
  class DirectoryDescriptor extends Descriptor implements LoadableDescriptor {
  
negative.code:           return (matchingEntries.first as ReadableDescriptor).read();
          } else {
            return (matchingEntries.first as LoadableDescriptor)
                .load(path.posix.joinAll(remainingPath));
          }
        }
      }));
  