anchor.diff:  
                   Assert.AreEqual(y, x)).QuickCheckThrowOnFailure()
   
  -(*
           [<Test>]
           let ``isEmpty``() =
               Spec.ForAny<int []>(fun (xs : int  []) ->
  
positive.code:                 let y = xs |> Array.isEmpty
  
                  Assert.AreEqual(x, y)).QuickCheckThrowOnFailure()
  *)
  
  module PerfTests = 
    let AdhocPerformanceTest() = 
  
negative.code:     runList() |> ignore
      runStream() |> ignore
        //0.3.0: 
        //   Real: 00:00:03.352, CPU: 00:00:03.343, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:02.631, CPU: 00:00:02.640, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:02.858, CPU: 00:00:02.843, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:03.156, CPU: 00:00:03.156, GC gen0: 0, gen1: 0, gen2: 0
        //
        //New (fully hidden represenations, without any inlining)
        //   Real: 00:00:17.211, CPU: 00:00:16.937, GC gen0: 1, gen1: 0, gen2: 0
        //   Real: 00:00:17.750, CPU: 00:00:17.687, GC gen0: 0, gen1: 0, gen2: 0
        //
        //New (fully hidden represenations, with inlining reducing to Internals)
        //   Real: 00:00:02.980, CPU: 00:00:02.968, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:02.961, CPU: 00:00:02.953, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:03.009, CPU: 00:00:03.015, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:02.952, CPU: 00:00:02.921, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:03.812, CPU: 00:00:03.796, GC gen0: 0, gen1: 0, gen2: 0
        //   Real: 00:00:03.483, CPU: 00:00:03.484, GC gen0: 0, gen1: 0, gen2: 0
  
  
  
  