anchor.diff:          { MockRenderer : unit }
   
       interface Renderer with
  -        member renderer.RenderContext = obj ()
  -        member renderer.TryLoadRenderAsset _ = None
           member renderer.PopMessages () = List ()
           member renderer.ClearMessages () = ()
           member renderer.EnqueueMessage _ = ()
  
positive.code: 
  /// The renderer. Represents the rendering system in Nu generally.
  and Renderer =
      /// The render context for custom rendering.
      abstract RenderContext : obj
      /// Attempt to load a render asset.
      abstract TryLoadRenderAsset : obj AssetTag -> RenderAsset option
      /// Pop all of the physics messages that have been enqueued.
      abstract PopMessages : unit -> RenderMessage List
      /// Clear all of the render messages that have been enqueued.
  
negative.code:         | _ ->
              Log.trace ("Render error - could not set render target to display buffer due to '" + SDL.SDL_GetError () + ".")
  
      /// Get the render context.
      static member getRenderContext renderer =
          renderer.RenderContext
  
      /// Make a Renderer.
      static member make renderContext =
          let renderer =
  