input: Write a python function to create an Employee object and test its methods.
  assert emp.get_name() == 'John Doe'
  assert emp.get_age() == 30
  assert emp.get_salary() == 50000
  emp.set_name('Jane Doe')
  emp.set_age(25)
  emp.set_salary(60000)
  assert emp.get_name() == 'Jane Doe'
  assert emp.get_age() == 25
  assert emp.get_salary() == 60000
output: class Employee:
      def __init__(self, name, age, salary):
          self.name = name
          self.age = age
          self.salary = salary
  
      def get_name(self):
          return self.name
  
      def get_age(self):
          return self.age
  
      def get_salary(self):
          return self.salary
  
      def set_name(self, name):
          self.name = name
  
      def set_age(self, age):
          self.age = age
  
      def set_salary(self, salary):
          self.salary = salary
  
  
  def test_employee():
      emp = Employee('John Doe', 30, 50000)
      assert emp.get_name() == 'John Doe'
      assert emp.get_age() == 30
      assert emp.get_salary() == 50000
      emp.set_name('Jane Doe')
      emp.set_age(25)
      emp.set_salary(60000)
      assert emp.get_name() == 'Jane Doe'
      assert emp.get_age() == 25
      assert emp.get_salary() == 60000