anchor.diff:            IsEnabled = true
             IsVisible = true
             EntitySemantic = Actor testFloorActor }
  -    
  -    let testEntityActorBlock = createTestBlock ()
   
       let testWorld_ = subscribe ClickTestButtonAddress [] (fun _ _ _ world -> let entityActorBlock = createTestBlock () in addEntityActorBlock entityActorBlock (TestGroupAddress @ [Lun.make (str (getNuId ()))]) world) testWorld
       let testWorld_ = addScreenX testScreen TestScreenAddress testWorld_
  
positive.code:     let testWorld_ = addGroup testGroup TestGroupAddress testWorld_
      let testWorld_ = addEntityGuiButton (testButtonGuiEntity, testButtonGui, testButton) TestButtonAddress testWorld_
      let testWorld_ = addEntityActorBlock (testFloorActorEntity, testFloorActor, testFloor) TestFloorAddress testWorld_
      let testWorld_ = addEntityActorBlock testEntityActorBlock TestBlockAddress testWorld_
      let hintRenderingPackageUse = HintRenderingPackageUse { FileName = "AssetGraph.xml"; PackageName = "Misc"; HRPU = () }
      { testWorld_ with RenderMessages = hintRenderingPackageUse :: testWorld_.RenderMessages }
  
  
negative.code:           ContactSound = { AssetName = Lun.make "Sound"; PackageName = Lun.make "Misc" }}
  
      let testBlockActor =
          { Position = Vector2 (400.0f, 200.0f)
            Size = Vector2 64.0f // TODO: look this up from bitmap file
            Rotation = 0.0f
            ActorSemantic = Block testBlock }
  