public TypingConfirmContentViewModel()
     : this(null)
 {
     DesignerSupport.ThrowIfNotInDesignMode();
 }
 public TypingPracticeItemContentViewModel()
     : this(null)
 {
     DesignerSupport.ThrowIfNotInDesignMode();
     this.SetPracticeItem(TypingPracticeItemContentViewModel.CreatePracticeItemInDesignMode());
 }