anchor.diff:      return objectStore.then((store) {
         GitOptions options = new GitOptions(root: entry, store: store);
         Pull pull = new Pull(options);
  -      return pull.pull().catchError((e) => SparkException.fromException(e));
  +      return pull.pull().catchError((e) => throw SparkException.fromException(e));
       });
     }
   
  
positive.code:       GitOptions options = new GitOptions(root: entry, store: store,
            username: username, password: password);
        return Push.push(options)
            .catchError((e) => SparkException.fromException(e));
      });
    }
  
    Future<List<String>> getDeletedFiles() {
      return objectStore.then((store) {
        return Status.getDeletedFiles(store)
            .catchError((e) => SparkException.fromException(e));
      });
    }
  
  
negative.code:       GitOptions options = new GitOptions(root: entry, store: store);
        Fetch fetch = new Fetch(new GitOptions(root: entry, store: store));
        return fetch.fetch()
            .catchError((e) => throw SparkException.fromException(e));
      });
    }
  
  