Student class

This class extends the Person class. It also has an additional instance variable and its accessor method: String studentNumber and public String getStudentNumber$().$

public Student $($Date born, Name name, String studentNumber$)$: This constructor throws IllegalPersonException exceptions if born or name is null; also, it throws IllegalPersonException exceptions if studentNumber is null, blank, or not nine characters long.

This class overrides the public String toString$()$ method, which returns a String in one of these two exact formats:

a$)$ Alive people example: "Tiger Woods $($student number: A$12345678)$ was born $1975-12-30$ and is still alive"

b$)$ Dead people example: "Albert Einstein $($student number: A$87654321)$ was born $1879-03-14$ and died $1955-04-18"$

Use the parent's getName$()$ return value, then its getPrettyName$()$ method, and the born$/$died getYyyyMmDd$()$ method.