HashMap Performance Improvements in Java 8
https://dzone.com/articles/hashmap-performance
https://javarevisited.blogspot.com/2016/01/how-does-java-hashmap-or-linkedhahsmap-handles.html
https://dzone.com/articles/hashmap-performance
https://javarevisited.blogspot.com/2016/01/how-does-java-hashmap-or-linkedhahsmap-handles.html