anchor.diff:      clazz = new Class(mirror.simpleName, superclass, _commentToHtml(mirror),
           interfaces.toList(), _variables(mirror.variables),
           _methods(mirror.methods), _annotations(mirror), _generics(mirror),
  -        mirror.qualifiedName, _isHidden(mirror), mirror.owner.qualifiedName,
  -        mirror.isAbstract);
  +        mirror.qualifiedName, _isHidden(mirror), mirror.owner.qualifiedName);
       if (superclass != null)
         clazz.addInherited(superclass);
       interfaces.forEach((interface) {
  
positive.code:     } else {
        subclasses.add(subclass.qualifiedName);
      }
    }
    
    /**
     * Check if this [Class] is an error or exception.
     */
    bool isError() {
      if (qualifiedName == 'dart.core.Error' || 
          qualifiedName == 'dart.core.Exception')
        return true;
      for (var interface in interfaces) {
        if (interface.isError()) return true;
      }
      if (superclass == null) return false;
      return superclass.isError();
    }
  
    /**
  
negative.code: 
    Typedef(String name, this.returnType, String comment, this.generics,
        this.parameters, this.annotations,
        String qualifiedName, bool isPrivate, String owner) : super(name, comment,
            qualifiedName, isPrivate, owner) {}
  
    Map toMap() => {
      'name': name,
  