Seeking Advice on Porting Python Classes to Mojo Structs

class Animal:
    def __init__(self, name):
        self.name = name  
    def whoareyou(self):
        return f"I am {self.name}!"
    def speak(self):
        raise NotImplementedError("Subclass must implement abstract method")

class Dog(Animal):
    def speak(self):
        return f"{self.name} says Woof!"

class Cat(Animal):
    def speak(self):
        return f"{self.name} says Meow!"

dog = Dog("Buddy")
cat = Cat("Whiskers")

print(dog.whoareyou()) # Output: I am Buddy!
print(cat.whoareyou()) # Output: I am Whiskers!
print(dog.speak())  # Output: Buddy says Woof!
print(cat.speak())  # Output: Whiskers says Meow!