anchor.diff:  module Giraffe.Tests.HttpHandlerTests
   
   open System
  +open System.Collections
   open System.IO
   open System.Collections.Generic
   open Microsoft.AspNetCore.Http
  
positive.code:         | None -> assertFailf "Result was expected to be %s" expected
          | Some ctx ->
              Assert.Equal(config.StatusCode, ctx.Response.StatusCode)
              if ctx.Response.StatusCode = 200 then
                  let body = getBody ctx
                  XmlAssert.equals expected body
                  Assert.Equal(config.ReturnContentType, ctx.Response |> getContentType)
  
negative.code: 
      let ctx = Substitute.For<HttpContext>()
      mockXml ctx
      mockJson ctx (Newtonsoft None)
      mockNegotiation ctx config.NegotiationConfig
      let app =
          GET >=> choose [
  