anchor.diff:  }
   
   class TreeDiffResult {
  -  Map<String, DiffEntry> entries = {};
  +  final Map<String, DiffEntry> entries = {};
   
     List<DiffEntry> getAddedEntries() => _getEntriesForType(DiffEntryType.ADDED);
     List<DiffEntry> getRemovedEntries() => _getEntriesForType(DiffEntryType.REMOVED);
  
positive.code:   /**
     * Expands given [treeEntries] into files.
     */
    Future<List<DiffEntry>> _expandDiffEntries(
        ObjectStore store, List<TreeEntry> diffEntries, String type) {
      List<DiffEntry> diffEntries = [];
      return Future.forEach(diffEntries, (DiffEntry diffEntry) {
  
negative.code:   /**
     * Expands a directory [treeSha] recursively.
     */
    static Future<List<DiffEntry>> _expandDiffEntry(
        ObjectStore store, String treeSha, String type) {
  
      List<DiffEntry> diffEntries = [];
  