internal void PopulateColChoicesLookup()
 {
     if (Cols != null)
     {
         ColChoicesLookup = Cols
                            .Where(answerItem => answerItem.Choices != null)
                            .SelectMany(a => a.Choices)
                            .ToDictionary(item => item.Id.Value, item => item.Text);
     }
 }