using WPF_1_Start.Config; namespace WPF_1_Start.Models; public class ReservationBook { private readonly List _reservations = []; public IEnumerable GetReservations(string username) { return _reservations.Where(r => r.Username!.Equals(username)); } public void AddReservation(Reservation reservation) { foreach (var existingReservation in _reservations.Where(existingReservation => existingReservation.Conflicts(reservation))) throw new ReservationException(existingReservation, reservation); _reservations.Add(reservation); } }