input: Write a python function to create a list of Employee objects and return their names.
  assert get_employee_names([Employee("Alice", 30, 70000), Employee("Bob", 25, 50000), Employee("Charlie", 35, 80000)]) == ["Alice", "Bob", "Charlie"]
  assert get_employee_names([Employee("David", 22, 40000), Employee("Eva", 28, 60000)]) == ["David", "Eva"]
  assert get_employee_names([]) == []
output: class Employee:
      def __init__(self, name, age, salary):
          self.name = name
          self.age = age
          self.salary = salary
  
  def get_employee_names(employees):
      return [employee.name for employee in employees]