Person

Write a Person class that describes a person in terms of their name and their age.

The Person class should have two constructors: one for a person with a specified name and a default age of 0, and one for a person with a specified name and age.

Write accessor methods for the two instance variables, getName() and getAge(), along with two mutator methods:

• celebrateBirthday(), which increases the person’s age by 1, and
• changeName(), which takes a single variable as a parameter and updates the instance variable to the new name.

Write a program PersonTester with a main() method that demonstrates creating and using the Person class.