https://stackoverflow.com/questions/6951895/what-does-and-mean-in-scala
https://www.marcinkossakowski.com/posts/2016-11-05-difference-between-functions-and-methods-in-scala.html
https://stackoverflow.com/questions/6951895/what-does-and-mean-in-scala
https://www.marcinkossakowski.com/posts/2016-11-05-difference-between-functions-and-methods-in-scala.html