anchor.diff:  
   open Yard.Generators.Common.AST
   open Yard.Generators.Common.AstNode
  +
  +open System
  +open System.IO
   open System.Collections.Generic
  +
  +
   open QuickGraph
   
   type BlockType = 
  
positive.code: 
          
          let stack = Stack<_>()
          let blockType = ref Start
          let blocksGraph = new CfgBlocksGraph<'TokenType>()
          let bStartVertex = ref CfgBlocksGraph<_>.StartVertex
          let bEndVertex = ref <| CfgBlocksGraph<_>.StartVertex + 1
  
negative.code:             
              out.WriteLine (sprintf ("%d -> %d") parentNumber nodeNumber)
  
              if isNew 
              then
                  block.children
                  |> List.iter (fun child -> printInterNode child nodeNumber)
  
  