C# (CSharp) GroupBy.ForEach примеры использования

Пример #1

 public override void ForEachChild(Action <IDmlfNode> action)
 {
     base.ForEachChild(action);
     Columns.ForEach(x => x.ForEachChild(action));
     if (OrderBy != null)
     {
         OrderBy.ForEach(x => x.ForEachChild(action));
     }
     if (GroupBy != null)
     {
         GroupBy.ForEach(x => x.ForEachChild(action));
     }
 }