anchor.diff:          new ResourceRegistry(Map.add key<'TResource> (box resource) index)
   
       /// Try Resolving resource of given type
  -    member __.TryResolve<'TResource> () = index.TryFind key<'TResource> |> Option.map unbox<'TResource>
  +    member __.TryResolve<'TResource> () = 
  +        match index.TryFind key<'TResource> with
  +        | Some boxedResource -> Some (unbox<'TResource> boxedResource)
  +        | None -> None
   
       /// Resolves resource of given type
       member __.Resolve<'TResource> () =
  
positive.code: [<AutoOpen>]
  module private ResourceRegistryUtils =
  
      let inline key<'T> = typeof<'T>.AssemblyQualifiedName
  
  /// Immutable dependency container used for pushing
  /// runtime resources to the continuation monad.
  
negative.code:     /// <summary>
      ///     Combines two resource registries into one.
      /// </summary>
      /// <param name="resources">Resources to be combined.</param>
      static member Combine(resources : seq<ResourceRegistry>) =
          let mutable index = Map.empty
          for r in resources do
  