Problem 3.13 from Java How to Program (11th edition)

Create a class called Employee that includes three instance variables—a first name (type String), a last name (type String) and a monthly salary (double).
Provide a constructor that initializes the three instance variables. Provide a set and a get method for each instance variable.
If the monthly salary is not positive, do not set its value.
Write a test app named EmployeeTest that demonstrates class Employee’s capabilities.
Create two Employee objects and display each object’s yearly salary.
Then give each Employee a 10% raise and display each Employee’s yearly salary again.