anchor.diff:              "pathname" =@ T<string>
               "search" =@ T<string>
               "hash" =@ T<string>
  -
  -            "resolveURL" => T<string> ^-> T<unit>
  +            "origin" =? T<string>
  +            "username" =@ T<string>
  +            "password" =@ T<string>
  +
           ]
   
       let UndoManager =
           Class "UndoManager"
           |+> Instance [
               "length" =? T<int>
  -            "item" => T<int> ^-> T<obj>
               "position" =? T<int>
  -            "add" => T<obj> * T<string> ^-> T<unit>
  +            "undo" => T<unit> ^-> T<unit>
  +            "redo" => T<unit> ^-> T<unit>
               "remove" => T<int> ^-> T<unit>
               "clearUndo" => T<unit> ^-> T<unit> 
               "clearRedo" => T<unit> ^-> T<unit> 
  
positive.code:                 Canvas.Repetition
                  Canvas.TextAlign
                  Canvas.TextBaseline
                  Canvas.TextMetrics
                  Elements.CanvasElement
                  Elements.HTMLAudioElement
  
negative.code:             "scrollbars" =? BarProp
              "statusbar" =? BarProp
              "toolbar" =? BarProp
  
  
              "frames" =? WindowProxyType
              "length" =? T<int>
  