anchor.diff:                  cls.UnionCases
                   |> Seq.mapi (fun i case ->
                       let constantCase v =
  +                        hasConstantCase <- true
                           if constants.Add(v) then
                               ConstantFSharpUnionCase v
                           else
  
positive.code:         Option.isSome baseCls || hasWSPrototype ckind clsMembers
  
      let mutable hasSingletonCase = false
  
      if annot.IsJavaScript || hasWSPrototype || isAugmentedFSharpType cls then
          if cls.IsFSharpUnion then
  
negative.code:                 )
                  |> List.ofSeq
              
              let i =
                  FSharpUnionInfo {
                      Cases = cases
  