F# wrapper for having AutoFixture perform post-processing on AutoFixture Specimens of a given type

WarmupCustomization.fs

type TypeThatIsARequestSpecification<'T>() =
    interface IRequestSpecification with
        member this.IsSatisfiedBy request = 
            match request with
            | :? System.Type as requestType -> typeof<'T>.IsAssignableFrom( requestType)
            | _ -> false
type PrepareSpecimenCommand<'T>( action) =
    interface ISpecimenCommand with
        member this.Execute( specimen, context) = 
            let instance = specimen :?> 'T
            action instance
type WarmupCustomization<'T>( prepareAction) = 
    interface ICustomization with
        member this.Customize fixture =
            fixture.Customizations.Add(
                new FilteringSpecimenBuilder(
                    Postprocessor(
                        MethodInvoker(
                            ModestConstructorQuery()),
                        PrepareSpecimenCommand<'T>( prepareAction)),
                    TypeThatIsARequestSpecification<'T>()))

WarmupExample.fs

type Context() as this =
    inherit AutoDataAttribute()
    let initializeSut (sut:IDynamicAllocationCache) =
        sut.Purge()
    do  this.Fixture.Customize <| WarmupCustomization initializeSut |> ignore