anchor.diff:      static member Where(test, pred: Func<_,_>) = 
           Test.filter pred.Invoke test
   
  +    /// Skip this test
       static member Skip(reason: string, [<ParamArray>] args: obj[]) =
           skiptest (String.Format(reason, args)) |> ignore
   
  +    /// Fail this test
       static member Fail(reason: string, [<ParamArray>] args: obj[]) =
           failtest (String.Format(reason, args)) |> ignore
positive.code:     static member List ([<ParamArray>] tests) =
          tests |> Seq.map Test.Case |> TestList
  
      static member List (name, setup: Func<_,_>, [<ParamArray>] tests) =
          let tests = tests |> Array.map (fun (name, test) -> Test.Case(name, setup.Invoke test))
          Test.List(name, tests)
  
      [<Extension>]
      static member Run tests = TestList tests |> run
  
      static member Fixture (setup: Func<_>, teardown: Action<_>) =
          if setup = null then nullArg "setup"
          if teardown = null then nullArg "teardown"
  
negative.code:                           Time = w.Elapsed }
              map execOne
  
      /// Runs a tree of tests, with parameterized printers (progress indicators) and traversal.
      /// Returns list of results.
      let eval (printer: TestPrinters) map tests =
          Test.toTestCodeList tests 
          |> evalTestList printer map
  