BUILD FAILED on Android Studio 1.5.1 / API 23.0.3 (Marshmallow)

Json doesn’t map on Java (since there’s no json class included with Java); The classes are plainly usable from java, in the sugar.json namespace (JsonObject and friends).[quote=“Loreto_Parisi, post:18, topic:7719”]
How to write this completion handler with no errors:
// this code generates a “No matching overload” error. let plainCallback: HttpResponseBlock! = { response in
} Http.ExecuteRequest(Url( url ), plainCallback)
[/quote]

I think it wants a HttpResponseBlock, not HttpResponseBlock! does it say something more as a hint?