d4Tests :: TestTree
d4Tests = decisionTestGroup "d4" "Accept-Language exists?"
  [ testCase "True ==> d5" $
      let rq = req { reqHeaders = HashMap.singleton hAcceptLanguage ["en"] }
      in after' d4 resource rq @?= Decision' "d5"
  , testCase "False ==> e5" $
      after' d4 resource req @?= Decision' "e5"
  ]
d4Tests :: TestTree
d4Tests = decisionTestGroup "d4" "Accept-Language exists?"
  [ testCase "True ==> d5" $
      let rq = req { reqHeaders = HashMap.singleton hAcceptLanguage ["en"] }
      in after' d4 resource rq @?= Decision' "d5"
  , testCase "False ==> e5" $
      after' d4 resource req @?= Decision' "e5"
  ]
d4Tests = decisionTestGroup "d4" "Accept-Language exists?"
  [ testCase "True ==> d5" $
      let rq = req { reqHeaders = HashMap.singleton hAcceptLanguage ["en"] }
      in after' d4 resource rq @?= Decision' "d5"
  , testCase "False ==> e5" $
      after' d4 resource req @?= Decision' "e5"
  ]