2019
https://www.javacodegeeks.com/2019/03/java-12-mapping-with-switch-expressions.html
https://www.infoq.com/articles/java-12-switch-expression

2018
https://blog.codefx.org/java/switch-expressions/
    https://habr.com/ru/post/443464/
http://marxsoftware.blogspot.com/2018/04/java-switch-expressions.html
http://marxsoftware.blogspot.com/2018/09/jdk-12-switch-expressions-in-action.html
http://marxsoftware.blogspot.com/2018/09/jdk12-switch-in-action.html
http://marxsoftware.blogspot.com/2018/09/jdk-12-switch-expression-enum.html