forked from loafle/openapi-generator-original
* [kotlin] Make API classes open (non-final) unless nonPublicApi is used By making those classes open, AspectJ can be used to enhance their behavior. I'm not changing kotlin-multiplatform templates, where 'open' was already present before my changes. Closes #22271 * Fail Kotlin sample compilation if API classes stop to be public Serves as a 'regression test'.