Yes it should be feasible. As I said before, with Flink 1.6 there will be better way for migrating a state, but for now you either need to lazily convert the state, or iterate over the keys and do the job manually.
So my question is: is that feasible to migrate state from `ProcessFunction` to my own operator then use `getKeyedStateBackend()` to migrate the states?
If yes, is there anything I need to be careful with? If no, why and can it be available in the future? Thank you.