anchor.diff:  
       interface IResource with
           member x.Level = x.Level
  +        member x.Inputs = inputs
           member x.Outputs = x.Outputs
           member x.Update() = x.Update()
           member x.NeedsUpdate(i,f) = x.NeedsUpdate(i,f)
  
positive.code:                     subscription.Value.Dispose()
                      subscription <- None
          )
  
      member x.DestroyCallbacks() =
          lock callbacks (fun () -> 
  
negative.code: open Microsoft.FSharp.NativeInterop
  
  open Aardvark.Base
  open Aardvark.Base.Rendering
  open Aardvark.Base.Incremental
  
  #nowarn "9"
  