public void Execute(object parameter)
 {
     if (parameter is TwoObjects)
     {
         TwoObjects pair = (TwoObjects)parameter;
         this._execute(pair.object1, pair.object2);
     }
 }
 public bool CanExecute(object parameter)
 {
     if (parameter is TwoObjects)
     {
         TwoObjects pair = (TwoObjects)parameter;
         return(CanExecute1(pair.object1) && CanExecute2(pair.object2));
     }
     return(true);
 }