anchor.diff:  """    
       =>  [ 2, 17, 5, 13
             3, 18, 5, 13
  -          4, 11, 5, 13 ]
  +          (4, 6, 5, 13) ]
   
   
   [<Test>]
  
positive.code: open G             // 25
  open H             // 26
  """
      => [ 2, 5, 3, 6
           5, 8, 19, 17
           8, 9, 9, 10
           11, 12, 14, 17
           16, 12, 19, 17
           17, 13, 18, 14
           21, 5, 23, 6
           25, 5, 26, 6 ]
  
  [<Test>]
  let ``hash directives``() =
  
negative.code:             interface IDisposable with  // 25
                  member __.Dispose() =
                      (docEventListener :> IDisposable).Dispose()
  """ 
      //|> parseTree
      => [ 2, 15, 27, 63     // MyModule
           4, 13, 5, 10
           7, 14, 15, 59     // Color
           13, 29, 15, 59
           (14, 19, 15, 59)
           (14, 31, 15, 59)
           17, 24, 27, 63    // MyInnerModule
           19, 24, 27, 63    // RecordColor
           25, 33, 27, 63
           (26, 23, 27, 63)
           (26, 35, 27, 63)]
      
  [<Test>]
  let ``open statements``() =
  