anchor.diff:    /// Collect test objects and run tests.
     member __.AsyncRunSynchronouslyAllTests progress tests = async {
       let! testResultsList = tests |> Seq.map (TestRunnerImpl.asyncRunSynchronouslyTest progress) |> TestRunnerImpl.asyncSequential
  -    let testResults = testResultsList |> Seq.collect (fun tr -> tr) |> Seq.toArray
  +    let testResults = testResultsList |> Array.collect id
       let errors = testResults |> Seq.sumBy TestRunnerImpl.countErrors
       return { Errors = errors; Results = testResults }
     }
  
positive.code:     }) |> Async.Parallel
  
    let asyncSequential xs = async {
      let list = new ResizeArray<'T>()
      for asy in xs do
        let! v = asy
        list.Add(v)
  
negative.code:   /// Collect test objects and run tests.
    member __.AsyncRunAllTests progress tests = async {
      let! testResultsList = tests |> Seq.map (TestRunnerImpl.asyncRunTest progress) |> TestRunnerImpl.asyncSequential
      let testResults = testResultsList |> Array.collect id
      let errors = testResults |> Seq.sumBy TestRunnerImpl.countErrors
      return { Errors = errors; Results = testResults }
    }
  