General
Java Lambda Expressions (With Examples)
https://www.programiz.com/java-programming/lambda-expressionLesson: Annotations (The Java™ Tutorials > Learning the Java Language)
https://docs.oracle.com/javase/tutorial/java/annotations/Java Nested and Inner Class (With Examples)
https://www.programiz.com/java-programming/nested-inner-classJava Static Keyword (With Examples)
https://www.programiz.com/java-programming/static-keywordDifference between static and non static nested class in Java - Inner class
https://www.java67.com/2012/10/nested-class-java-static-vs-non-static-inner.htmlWhat is an Inner Interface in Java? - DZone Java
https://dzone.com/articles/what-inner-interface-java