class Dog:
    def speak(self):
        return "Woof!"

class Cat:
    def speak(self):
        return "Meow!"

def animal_sound(animal):
    return (animal.speak())

print(f" My dog says, {animal_sound(Dog())}")  # Woof!
print(f" My cat says, {animal_sound(Cat())}")  # Meow!