anchor.diff:              let msg = sprintf "Resource '%s' not installed in this context." typeof<'TResource>.Name
               raise <| ResourceNotFoundException msg
   
  -    /// Returns true iff registry instance contains resource of given type
  +    /// Returns true iff registry instance contains resource of given type.
       member __.Contains<'TResource> () = index.ContainsKey key<'TResource>
   
  -    /// Creates an empty resource container
  +    /// Gets the empty resource container.
       static member Empty = empty
   
       /// <summary>
  
positive.code:     member __.Remove<'TResource> () : ResourceRegistry =
          new ResourceRegistry(Map.remove key<'TResource> index)
  
      /// Try Resolving resource of given type
      member __.TryResolve<'TResource> () : 'TResource option = 
          match index.TryFind key<'TResource> with
          | Some boxedResource -> Some (unbox<'TResource> boxedResource)
          | None -> None
  
      /// Resolves resource of given type
      member __.Resolve<'TResource> () : 'TResource =
          match index.TryFind key<'TResource> with
          | Some boxedResource -> unbox<'TResource> boxedResource
  
negative.code:     // ResourceRegistry indexes by Type.AssemblyQualifiedName which is expensive to obtain.
      // Memoize for better resolution performance.
      let dict = new System.Collections.Concurrent.ConcurrentDictionary<Type, string>()
      let inline key<'T> : string = dict.GetOrAdd(typeof<'T>, fun t -> t.AssemblyQualifiedName)
  
  /// Immutable dependency container used for pushing
  /// runtime resources to the continuation monad.
  