/// <summary>
 /// Convert to node models
 /// </summary>
 /// <param name="context"></param>
 /// <param name="collection"></param>
 /// <returns></returns>
 public static IEnumerable <BaseNodeModel> ToNodeModels(this NodeStateCollection collection,
                                                        ISystemContext context)
 {
     return(collection.Select(n => n.ToNodeModel(context)));
 }