https://docs.google.com/presentation/d/1uItKUU8BDI8qSh_T8EO_0DWO34rKJtiO9nuoIj_VduE/edit?usp=sharing
cs61b 2019 lec11 inheritance4 equals, exceptions, iterations, lists, sets, maps - Google Slides
CS61B: 2019 Lecture 11: The End of Java Lists and Sets Exceptions Iteration toString and Equals