class A:
    def __init__(self, value):
        self.value = value
        
    def __repr__(self):
        return f'A (value={self.value})'

def deco(fn):
    def wrapper(*args, **kwargs):
        return A(fn(*args, **kwargs))
    return wrapper

@deco
def add(a, b):
    return a + b
    
print(add(10, 20))