anchor.diff:      static member OfSize (sizedGen : Func<int,Gen<_>>) =
           sized <| fun s -> (sizedGen.Invoke(s))
   
  -
  +///Methods to build shrinkers.
   type Shrink =
       ///Returns the immediate shrinks for the given value based on its type.
       static member Type<'a>() = shrink<'a>
   
  -//mutable counterpart of the Config type
  +///Configure the test run.
   type Configuration() =
       let mutable maxTest = Config.Quick.MaxTest
       let mutable maxFail = Config.Quick.MaxFail
  
positive.code:         SpecBuilder<'a,'b,'c>( generator0, shrinker0, generator1, shrinker1,generator2, shrinker2, 
              (fun a b c -> (assertion0 a b c) .|. (label name (assertion.Invoke(a,b,c)))), conditions, collects, classifies)  
        
                  
  type Spec() =
      static let _ = Runner.init.Value
      static let noshrink = fun _ -> Seq.empty
      static member ForAny(assertion:Func<'a,bool>) =
  
negative.code:     static member ToArbitrary (generator,shrinker) =
          Arb.fromGenShrink (generator,shrinker)
  
  ///Extensons to transform Arbitrary instances into other Arbitrary instances.
  [<System.Runtime.CompilerServices.Extension>]
  type ArbitraryExtensions =
      ///Construct an Arbitrary instance for a type that can be mapped to and from another type (e.g. a wrapper),
  