after migration to jdk21 https://github.com/checkstyle/checkstyle/issues/17430 activate MissingNullCaseInSwitch https://checkstyle.sourceforge.io/checks/coding/missingnullcaseinswitch.html#MissingNullCaseInSwitch and follow it
after migration to jdk21 #17430
activate MissingNullCaseInSwitch
https://checkstyle.sourceforge.io/checks/coding/missingnullcaseinswitch.html#MissingNullCaseInSwitch
and follow it