anchor.diff:        m['classes'] == null
             ? null
             : new List.from(
  -              m['classes'].map((obj) => ImplementedClass.parse(obj))),
  +          m['classes'].map((obj) => ImplementedClass.parse(obj))),
         m['members'] == null
             ? null
             : new List.from(
  -              m['members'].map((obj) => ImplementedMember.parse(obj))));
  +          m['members'].map((obj) => ImplementedMember.parse(obj))));
   
     final String file;
     final List<ImplementedClass> classes;
  
positive.code:   RefactoringProblem(this.severity, this.message, {this.location});
  }
  
  class RemoveContentOverlay implements Jsonable {
    static RemoveContentOverlay parse(Map m) {
      if (m == null) return null;
      return new RemoveContentOverlay(m['type']);
    }
  
    final String type;
  
    Map toMap() => _stripNullValues({'type': type});
  
    RemoveContentOverlay(this.type);
  }
  
  class SearchResult {
  
negative.code:       m['targets'] == null
            ? null
            : new List.from(
            m['targets'].map((obj) => NavigationTarget.parse(obj))),
        m['regions'] == null
            ? null
            : new List.from(
            m['regions'].map((obj) => NavigationRegion.parse(obj))));
  
    final List<String> files;
    final List<NavigationTarget> targets;
  