Inheritance: TextElement, IBlock
 public virtual void Add(Block block)
 {
     var richTextBlock = new RichTextBlock
     {
         Margin = new Thickness(5)
     };
     richTextBlock.Blocks.Add(block);
     Add(richTextBlock);
 }
 public void Add(Block paragraph)
 {
     _richTextBlock.Blocks.Add(paragraph);
 }
 public void Add(Block paragraph)
 {
     throw new NotSupportedException();
 }
 public void Add(Block block)
 {
     var richTextBlock = new RichTextBlock();
     richTextBlock.Blocks.Add(block);
     Add(richTextBlock);
 }
 public static void SetMessageText(DependencyObject obj, Block value)
 {
     obj.SetValue(MessageTextProperty, value);
 }
 public void Add(Block block)
 {
     _innerContainer.Add(block);
 }
 public virtual void Add(Block block)
 {
     _richTextBlock.Blocks.Add(block);
 }