private void OnContactUpdated(ModelUpdatedMessageResult <Contact> updateResult)
        {
            RecentContacts.UpdateCollection(updateResult.UpdatedModel, updateResult.UpdateEvent);

            if (RecentContacts.Count == 1 && !CurrentUser.HasShownFirstContactAchievementPrompt)
            {
                ShowFirstContactPrompt();
            }
        }
        private async void RemoveContact(Contact contact)
        {
            var result = await UserNotifier.ShowConfirmAsync("Are your sure you want to delete this contact?", "delete contact", "yes");

            if (result)
            {
                var deleteResult = await _repository.DeleteContactAsync(contact);

                if (deleteResult.IsValid())
                {
                    RecentContacts.UpdateCollection(contact, ModelUpdateEvent.Deleted);
                }
            }
        }