anchor.diff:        .asyncMap((e) async {
           var file = new File(p.join(e.path, 'pubspec.yaml'));
           print('checking if exists on $file');
  -        return await file
  -          .exists() ? new Some(e) : const None();
  +        return await file.exists() ? new Some(e) : const None();
         })
         .where((o) => o is Some)
         .map((o) => o.get());
  
positive.code: 
      await layout.groupDirectory.create(recursive: true);
  
      await metaData.save(layout.groupDirectory);
  
      return layout.containerDirectory;
  
negative.code:       _installOrUpdate(parentDir, gitUri, name: name, updateIfExists: true);
  
    static Future<Directory> jefetize(Directory parentDirectory) async {
      Future<Directory> massageContainerDirectory() async {
        if (!parentDirectory.path
            .endsWith(GroupDirectoryLayout._containerSuffix)) {
  