protected async override void OnAppearing()
        {
            base.OnAppearing();
            await this.viewModel.Init();

            await TrackerProgressBar.ProgressTo(this.viewModel.Percentage, 900, Easing.Linear);
        }
        private async void Button_Clicked(object sender, System.EventArgs e)
        {
            await this.viewModel.AddPages();

            await this.viewModel.Init();

            await TrackerProgressBar.ProgressTo(this.viewModel.Percentage, 900, Easing.Linear);
        }