/home/paul/doc/dev/Pony/pony-ws/testy.pony:40:45: argument not a subtype of parameter
            let _parent: TestWSNotify ref = this
                                            ^
    Info:
    /home/paul/doc/dev/Pony/pony-ws/testy.pony:40:45: TestWSNotify tag is not a subtype of TestWSNotify ref: tag is not a subcap of ref
                let _parent: TestWSNotify ref = this