Mapping Some to None

[G4143]

In your enclosed examples of mapping optional types, you don't have an example which maps a Some[value] to a None. How do you accomplish that?

Some["caterpillar!"].map(&:upcase) # => Some["CATERPILLAR!"]
None.map(&:upcase) # => None

How do I accomplish
Some["caterpillar!"].map(do something to produce a None) # => None