Spring PetClinic diagram sample don't work: This funciton does not have any !return directive

[jrichardsz]

I tried this https://github.com/robbell/plantuml-c4/blob/master/samples/pet-clinic-sample.puml in the official plantuml server (https://www.plantuml.com/plantuml) and I got this error:

The example on readme, works:

https://github.com/robbell/plantuml-c4#example