private User ChangeCurrentTown(string username, string townName) { if (!townService.Exist(townName)) { throw new ArgumentException($"Value {townName} not valid.{Environment.NewLine}" + $"Town {townName} not found!"); } User user = context.Users.First(u => u.Username == username); user.CurrentTown.Name = townName; context.SaveChanges(); return(user); }