Function mapUpdateKeyCopying

mapUpdateKeyCopying(
    map: Thing<map>,
    key: Thing,
    item: Thing,
    opTrace?: LocationTrace,
): Thing<map>
Return a new Backolon map with the given key inserted or updated. The original map is not modified.
Parameters
- map: Thing<map>
- key: Thing
- item: Thing
- OptionalopTrace: LocationTrace
Returns Thing<map>