Programming its purpose

1. a. Create an ArrayList, HashMap and HashSet Objects. [3 marks] b. Add 2 entries to each one of them using an appropriate method. 2. Complete the constructor in Message class to initialize fields correctly. 12 marks! public class Mail public class Message extends private String sender; Mail! private String receiver; private String mg; public Mail (String s, String public Message (String r) sender, String receiver, String msg) sender - S; //TODO: Complete the constructor receiver - ri