title: Kafka Key access on Ingress of a Python Flink Stateful function
body: <p>I've been looking at Flink Stateful Functions. It looks super promising - except for one thing - and I hope I'm just missing it.</p>
  <p>For the life of me, can't see a way to access the kafka key from a kafka ingress in Python. In Java, I see I could use the deserialiser and effectively pack it into the decoded <code>message</code> object. But I can't find an alternative.<br />
  In our case, the key has valuable info, that does not exist in the value.</p>
  <p>Anyone come across this - or have I just missed it?</p>