/// <summary>
        /// Handles the user clicking the "Ask to lunch" button.
        /// </summary>
        public async void AskToLunch()
        {
            var location = SelectedLocation.Name == "Custom"
                ? new Location {
                Name = CustomLocation
            }
                : SelectedLocation;
            var lunch = new Lunch(Name,
                                  App.User,
                                  SelectedFriends.Concat(new[] { App.User }),
                                  location,
                                  SelectedDate.Add(SelectedTime).LocalDateTime);
            await App.Api.PostAsync("Lunch", lunch);

            ShellViewModel.Current.Navigate(typeof(Lunches));
        }