Custom case formatter and preserving char casing

[olivernybroe]

I have a use case where I want to format a string away from camel_case etc. but not remove the casing of each word.

E.g. If someone wrote this_is_Kotlin, I can change it to this is Kotlin.

Current solution is "this_is_Kotlin".splitToWords().joinToString(" "), however not able to do it with the custom case formatter, or at least haven't figured out how.