1. Lambda Expressions
2. Functional Interfaces
3. Default methods in Functional Interfaces
4. Static methods in Functional Interfaces
5. Predefined Functional Interfaces
6. Predicate
7. Consumer
8. Producer
9. :: operator
10. Streams

https://github.com/winterbe/java8-tutorial

https://winterbe.com/posts/2015/03/15/avoid-null-checks-in-java/

https://winterbe.com/posts/2018/09/24/java-11-tutorial/