I can't directly log a image

[iOSleep]

I'm in a swift proj, i can't call

let img = UIImage(named: "launch")
Log(.View, .Debug, img)

xcode will tell error Cannot convert value of type 'UIImage?' to expected argument type 'String'

I find the func Log's argument format is type if @autoclosure () -> String, that means i should do img?.description to call Log ?

what should i do to call Log func with types like String but not like Any.description