如何将属性添加到基类的属性

class BaseClass:
    def __init__(self, name):
        self.name = name

class SubClass(BaseClass):
    def __init__(self, name, age):
        super().__init__(name)
        self.age = age

def add_property(cls):
    def wrapper(*args, **kwargs):
        instance = cls(*args, **kwargs)
        instance.age = None
        return instance
    return wrapper

@add_property
class BaseClass:
    def __init__(self, name):
        self.name = name

class MetaClass(type):
    def __new__(cls, name, bases, dct):
        dct['age'] = None
        return super().__new__(cls, name, bases, dct)

class BaseClass(metaclass=MetaClass):
    def __init__(self, name):
        self.name = name