anchor.diff:      // Exercise system
       sut.Customize(fixtureStub)
       // Verify outcome
  -    Assert.Empty(customizations)
  +    verify <@ customizations |> Seq.isEmpty @>
       // Teardown
   
  
positive.code:     // Exercise system
      let sut = AutoFoqCustomization()
      // Verify outcome
      Assert.IsAssignableFrom<ICustomization>(sut)
      // Teardown
  
  [<Fact>]
  let InitializeWithNullRelayThrows() =
      // Fixture setup
      // Exercise system and verify outcome
      Assert.Throws<ArgumentNullException>(fun () -> 
          AutoFoqCustomization(null) |> ignore)
      // Teardown
  
  [<Fact>]
  
negative.code:     // Exercise system
      let result = sut.Relay
      // Verify outcome
      verify <@ result.GetType() = typeof<FilteringSpecimenBuilder> @>
      // Teardown
  
  [<Fact>]
  