anchor.diff:          ]
   
       let LayerEvent =
  -        Interface "L.LayerEvent"
  -        |=> Extends [Event]
  -        |+> [
  +        Class "L.LayerEvent"
  +        |=> Inherits Event
  +        |+> Protocol [
               "layer" =? ILayer
               |> WithComment "The layer that was added or removed."
           ]
   
       let LayersControlEvent =
  -        Interface "L.LayersControlEvent"
  -        |=> Extends [Event]
  -        |+> [
  +        Class "L.LayersControlEvent"
  +        |=> Inherits Event
  +        |+> Protocol [
               "layer" =? ILayer
               |> WithComment "The layer that was added or removed."
               "name" =? T<string>
  
positive.code:         ]
  
      let ResizeEvent =
          Interface "L.ResizeEvent"
          |=> Extends [Event]
          |+> [
              "oldSize" =? Point
              |> WithComment "The old size before resize event."
              "newSize" =? Point
  
negative.code:         ]
  
      let TileEvent =
          Class "L.TileEvent"
          |=> Inherits Event
          |+> Protocol [
              "tile" =? T<Element>
              |> WithComment "The tile element (image)."
              "url" =? T<string>
  