protected override bool OnBackButtonPressed()
 {
     if (ShouldOverrideBackButton)
     {
         PageClosedTaskCompletionSource.SetResult(default(T));
     }
     return(true);
 }
 // Invocked when background is clicked
 protected override bool OnBackgroundClicked()
 {
     // Prevent background clicked action
     //return base.OnBackgroundClicked();
     if (ShouldOverrideBackButton)
     {
         PageClosedTaskCompletionSource.SetResult(default(T));
     }
     return(false);
 }