I'm using this class for Kafka deserialization and I'd like to wrap/extend it in some clean way so that result implements

Deserializer<GenericRecord>

instead of

Any

What approaches can I use for that?

I had a look, that particular implementation is to deserialize arbitrary data/types. If you want a type specific wrapper what you'd need to do is have that wrapper forward the request, and then cast the result to the actual type. Alternatively you could do explicit error handling (wrong type)