Flink State Processor API with Windowed CoGroup and Unaligned Checkpoints

1. How can I use the Flink State Processor API to process the state of a windowed CoGroup (or Join) function? The documentation does not give such an example.
2. Is there a way to use the Flink State Processor API to process unaligned checkpoints?

1. Not sure this is doable.
2. No, this isn't possible. (In general, the on-the-wire serializer needn't be the same as the state serializer. Unaligned checkpoints can include copies of inflight data that the state processor API can't deserialize.)

See the table in the docs showing the capabilities and limitations of checkpoints vs savepoints for more info on what's possible with the state processor API.