input: Write a python function to calculate the total compensation (salary + bonus) for an Employee object.
  assert calculate_total_compensation(Employee("Alice", 30, 50000, "Engineer").set_bonus(5000)) == 55000
  assert calculate_total_compensation(Employee("Bob", 45, 70000, "Manager").set_bonus(10000)) == 80000
  assert calculate_total_compensation(Employee("Charlie", 28, 40000, "Analyst").set_bonus(3000)) == 43000
output: class Employee:
      def __init__(self, name, age, salary, position):
          self.name = name
          self.age = age
          self.salary = salary
          self.position = position
          self.bonus = 0
  
      def set_bonus(self, bonus):
          self.bonus = bonus
          return self
  
  def calculate_total_compensation(employee):
      return employee.salary + employee.bonus