anchor.diff:      override this.RunAsync(diagnosticMessageSink:IMessageSink, messageBus:IMessageBus, constructorArguments:obj [], aggregator:ExceptionAggregator, cancellationTokenSource:Threading.CancellationTokenSource) =
           let test = new XunitTest(this, this.DisplayName)
           let summary = new RunSummary(Total = 1);
  -
  +        let outputHelper = new TestOutputHelper()
  +        outputHelper.Initialize(messageBus, test)
           let testExec() =
  -            let config = this.Init()
  +            
  +            let config = this.Init(outputHelper)
               let timer = ExecutionTimer()
               let result =
                   try
  
positive.code:     interface IRunner with
          override __.OnStartFixture _ = ()
          override __.OnArguments (ntest,args, every) =
              printf "%s" (every ntest args)
          override __.OnShrink(args, everyShrink) =
              printf "%s" (everyShrink args)
          override __.OnFinished(_ ,testResult) =
              result <- Some testResult
  
  
negative.code: 
      new() = new PropertyTestCase(null, TestMethodDisplay.ClassAndMethod, null)
  
      member this.Init(output:TestOutputHelper) =
          let factAttribute = this.TestMethod.Method.GetCustomAttributes(typeof<PropertyAttribute>) |> Seq.head
          let arbitrariesOnMethod = factAttribute.GetNamedArgument "Arbitrary"
          let arbitrariesOnClass =
  