anchor.diff:  
       let transformAttachedProperty (com: IBabelCompiler) ctx (info: Fable.AttachedMemberInfo) getter setter =
           let funcExpr (args, body) =
  -            let boundThis, args = prepareBoundThis "this" args
  -            let args, body, returnType, typeParamDecl = getMemberArgsAndBody com ctx None boundThis args false body
  +            let thisArg, args = splitThisArg args
  +            let args, body, returnType, typeParamDecl =
  +                getMemberArgsAndBody com ctx None thisArg args false body
               makeFunctionExpression None (args, U2.Case1 body, returnType, typeParamDecl)
           let getterFuncExpr = Option.map funcExpr getter
           let setterFuncExpr = Option.map funcExpr setter
  
positive.code:                 if not isThisUsed
                  then args, body, genTypeParams
                  else
                      // If the boundThis is the actual JS `this` keyword bind it at the beginning
                      // to prevent problems in closures. If not, replace thisArg in body with boundThis.
                      let boundThisExpr = { thisArg with Name = boundThis } |> Fable.IdentExpr
                      let body =
                          if boundThis = "this"
                          then Fable.Let([thisArg, boundThisExpr], body)
                          else FableTransforms.replaceValues (Map [thisArg.Name, boundThisExpr]) body
                      args, body, genTypeParams
              | None -> args, body, Set.empty
          let ctx = { ctx with ScopedTypeParams = Set.union ctx.ScopedTypeParams genTypeParams }
  
negative.code:         declareType com ctx r info.IsPublic info.Entity info.EntityName args body baseExpr
  
      let transformImplicitConstructor (com: IBabelCompiler) ctx r (info: Fable.ClassImplicitConstructorInfo) =
          let thisArg = Some info.BoundConstructorThis
          let consIdent = Identifier(info.EntityName) :> Expression
          let args, body, returnType, typeParamDecl =
              getMemberArgsAndBody com ctx None thisArg info.Arguments info.HasSpread info.Body
          let returnType, typeParamDecl =
              // change constructor's return type from void to entity type
              if com.Options.typescript then
  