anchor.diff:    /**
      * Expands a directory [treeSha] recursively.
      */
  -  Future<List<DiffEntry>> _expandDiffEntry(
  +  static Future<List<DiffEntry>> _expandDiffEntry(
         ObjectStore store, String treeSha, String type) {
   
       List<DiffEntry> diffEntries = [];
  
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: }
  
  class TreeDiffResult {
    final Map<String, DiffEntry> entries = {};
  
    List<DiffEntry> getAddedEntries() => _getEntriesForType(DiffEntryType.ADDED);
    List<DiffEntry> getRemovedEntries() => _getEntriesForType(DiffEntryType.REMOVED);
  