How do I add data to a MAP in a persistent INSERT INTO or CSAS query?

I’d like to add data to a MAP in an INSERT INTO SELECT FROM… EMIT CHANGES statement or in a CREATE STREAM AS SELECT query from the stream being selected from. Is this possible, or can it only be done via an INSERT VALUES statement?

If it is possible, please provide / point to an example. I’ve scoured kslqdb.io docs and can’t find anything.

Thanks,
Jim