Thanks for the illustrative example.
Ahh ya, mapTypes is an object that also contains a lot of other things
besides the map types. In your example you are looking for the
property tileSize to extract the map types. It is not documented that
the name of these extracted map type objects can be accessed with the
property name. There is also no method getName() like in v2.
Do you know if the mapTypes object will also contain a previously
added additional map type?
I'm asking because the reference seems not clear in this case. Another
map property besides mapTypes is mentioned, namely overlayMapTypes.