public ArgValueSet(string key, ArgSet <object> argSet)
     : base(key, default(T))
 {
     if (!(argSet == null))
     {
         this.argSet = argSet;
     }
 }
 public ArgValueSet(string key, T value, ArgSet <object> argSet)
     : base(key, value)
 {
     if (!(argSet == null))
     {
         this.argSet = argSet;
     }
 }