2. Suppose you're working on payroll system. Define a class Employee representing employees of a company. Employees have the following properties: first name, last name, id number, and salary. Your class should have instance variables of appropriate types with getters and setters for these properties. Your class should have two constructors: one takes all the properties, one takes only first and last names and sets the id number and salary to some reasonable default. . Your class should have a method raise that increments the employee's salary by the given amount (decrements if the amount is negative) . Your class should have an informative tostring method. Include a separate class that tests the use of your Employee class, including giving an employee a 10% raise