anchor.diff:              duration = TimeSpan.Zero }
           | _ ->
             next (name, test, wrappedFocusedState)
  +
  +      /// Used to constrain parallelism for tests that cannot be run parallel
  +      /// with correct results, such as Expect.isFasterThan or `benchmark<..>`
  +      /// based tests. Note; this does not give an ordering guarantee.
  +      let maybeSequence next (name, test, wrappedFocusedState) =
  +        try
  +          // here Anthony
  +          enterLock () (*locks*) (name, test)
  +          next (name, test, wrappedFocusedState)
  +        finally
  +          exitLock () (*locks*) (name, test)
   
         let execOne (name: string, test: TestCode, wrappedFocusedState: WrappedFocusedState) =
           let w = System.Diagnostics.Stopwatch.StartNew()
  
positive.code:           let wrappingMethod = if existsFocusedTests then applyFocusedWrapping else Enabled
            testsList |> Seq.map (fun (n, t, s) -> (n, t, wrappingMethod s))
  
    /// Runs a list of tests, with parameterized printers (progress indicators) and traversal.
    /// Returns list of results.
    let evalTestList =
  
negative.code:       else
          None
  
      fun (printers: TestPrinters) (* locks : Locks *) map ->
  
        let beforeOne (name: string, test, wrappedFocusedState) =
          printers.beforeEach name
  