anchor.diff:          ]
   
       let DragEvent =
  -        Pattern.EnumStrings "DragEvent" [
  +        EnumStrings "DragEvent" [
               "dragstart"
               "drag"
               "dragend"
           ]
  -        |>! addToClassList
   
       let Drag =
           ChainedClassNew "Drag" <| fun chained ->
  
positive.code:             "selectAll"  => chained selector
          ]
  
      addToClassList (
          Class "UpdateSelection"
          |=> UpdateSelection
          |=> Inherits Selection
  
negative.code:         ]
  
      let ZoomEvent =
          EnumStrings "ZoomType" [
              "zoomstart"
              "zoom"
              "zoomend"
          ]
  
      let Zoom =
          ChainedClassNew "Zoom" <| fun chained ->
  