anchor.diff:    member __.Parameters = metadata.Parameters
     /// Execute the test.
     member __.Run() = 
  -    let watch = Stopwatch()
  -    watch.Start()
  +    let watch = Stopwatch.StartNew()
       let result = body ()
       watch.Stop()
       match result with
  
positive.code:                   assertionResults
                    |> NonEmptyList.toList
                    |> AssertionResult.List.onlyNotPassed
                  let watch = Stopwatch()
                  try
                    match notPassed with
                    | [] -> failwith "oops!"
                    | head::tail ->
                        assert (typeof<'T> = typeof<unit>)
                        watch.Start()
                        // continue the test!
                        let testRes = (rest Unchecked.defaultof<'T>).Run()
                        testRes
  
negative.code:           fun () ->
              match x.Run() with
              | Done (meta, (Passed value, []), duration) ->
                  let watch = Stopwatch.StartNew()
                  try (rest value).Run()
                  with e ->
                    watch.Stop()
  