old_contents: # -*- coding:utf-8 -*-
  
  ## Animal is a object(yes, sort of confusing) look at th extra credit.
  
  class Animal(object):
      """A New class calls animal"""
      pass
  
  class Dog(Animal):
      """docstring for Dog"""
      def __init__(self, name):
          self.name = name
  
  
  class Cat(Animal):
      """docstring for Cat"""
      def __init__(self, name):
          self.name = name
  
  
  class Person(object):
      """docstring for Person"""
      def __init__(self, name):
          
          self.name = name
          self.pet = None
  
  
  class Emplyee(Person):
      """docstring for Emplyee"""
      def __init__(self, name, salary):
          super(Emplyee, self).__init__(name)
          self.salary = salary
  
  
  class Fish(object):
      """docstring for Fish"""
      pass
  
  
  class Salmon(Fish):
      pass
  
  
  class Halibut(Fish):
      pass
  
  ## rover is a Dog
  
  rover = Dog('rover')
  satan = Cat('Satan')
  mary = Person('Mary')
  
  
new_contents: # -*- coding:utf-8 -*-
  
  ## Animal is a object(yes, sort of confusing) look at th extra credit.
  
  class Animal(object):
      """A New class calls animal"""
      pass
  
  class Dog(Animal):
      """docstring for Dog"""
      def __init__(self, name):
          self.name = name
  
  
  class Cat(Animal):
      """docstring for Cat"""
      def __init__(self, name):
          self.name = name
  
  
  class Person(object):
      """docstring for Person"""
      def __init__(self, name):
          
          self.name = name
          self.pet = None
  
  
  class Emplyee(Person):
      """docstring for Emplyee"""
      def __init__(self, name, salary):
          super(Emplyee, self).__init__(name)
          self.salary = salary
  
  
  class Fish(object):
      """docstring for Fish"""
      pass
  
  
  class Salmon(Fish):
      pass
  
  
  class Halibut(Fish):
      pass
  
  ## rover is a Dog
  
  rover = Dog('rover')
  satan = Cat('Satan')
  mary = Person('Mary')
  
subject: add some examples