private PropertyChangedListener CreatePropertyChangedListener(IChecklistQuestionField field)
        {
            if (field == null)
                return null;

            var propertyChangedListener = new PropertyChangedListener(this, field)
                                          {
                                              OnEventAction = OnQuestionFieldPropertyChanged,
                                              OnDetachAction = Static
            };
            field.PropertyChanged += propertyChangedListener.OnEvent;

            return propertyChangedListener;
        }
 private bool IsSelected(IChecklistQuestionField field)
 {
     return Model.QuestionField.IsMatch(new ChecklistQuestionFieldInfo(field.Guid, field.SystemName, field.QuestionSource));
 }