anchor.diff:    }  
     
     void setDirty(String fieldName) {
  -    if (_dirtiFields === null){
  +    if (_dirtyFields === null){
         return;
       }
  -    _dirtiFields.add(fieldName);
  +    _dirtyFields.add(fieldName);
     }
     
     void clearDirtyStatus() {
  -    _dirtiFields.clear();
  +    _dirtyFields.clear();
     }
     
     void onValueChanging(String fieldName, newValue) {
  
positive.code:     map = newValue;
      _initMap();
      init();
      _dirtiFields = new Set<String>();    
    }
    
    EmbeddedPersistentObject getEmbeddedObject(String className, String property) {
      EmbeddedPersistentObject result = _compoundProperties[property];
      if (result == null) {
  
negative.code:   void setDirty(String fieldName){
      super.setDirty(fieldName);
      if (_parent !== null) {
        _parent.setDirty('${_pathToMe}.${fieldName}');
      }
    }
    remove() {
  