Generated rinpop adapter does not compile when there is service extension

[chucknthem]

service Foo {
   string ping()
}

service Bar extends Foo {
}

The generated code fails with this error:

cannot use adapter (type *RingpopBarAdapter) as type TChanBar in return argument:
	*RingpopBarAdapter does not implement TChanBar (missing Ping method)

Examples of how tchannel-go thrift gen template handles it https://github.com/uber/tchannel-go/blob/dev/thrift/thrift-gen/tchannel-template.go#L55
https://github.com/uber/tchannel-go/blob/dev/thrift/thrift-gen/tchannel-template.go#L45

[proflayton]

I am also seeing the same problem. Can we prioritize this?