protected SyntaxTreeNodeViewModel(SyntaxTreeNode baseNode)
 {
     Offset = baseNode.Start.Offset;
     Line = baseNode.Start.Line;
     Column = baseNode.Start.Column;
     Length = baseNode.Length;
 }
 public static SyntaxTreeNodeViewModel CreateViewModel(SyntaxTreeNode node)
 {
     Block b = node as Block;
     if (b != null)
     {
         return new BlockViewModel(b);
     }
     else
     {
         return new SpanViewModel((Span)node);
     }
 }