internal void Add(Frame region) { if (String.IsNullOrWhiteSpace(region.Name)) { throw new ArgumentNullException("Name"); } if (Navigations.ContainsKey(region.Name)) { Logger.Technical.From <RegionManager>().System($"A region with name: {region.Name} is already registered.").Log(); throw new DuplcateRegionException(region.Name); } Navigations.Add(region.Name, new NavigationService(region)); }