public TResult Accept <TResult>(
     IReservationsInstructionVisitor <T, TResult> visitor)
 {
     return(visitor.VisitReadReservations(date, continuation));
 }
 public TResult Accept <TResult>(
     IReservationsInstructionVisitor <T, TResult> visitor)
 {
     return
         (visitor.VisitIsReservationInFuture(reservation, continuation));
 }