How to correcly declare method in concrete class (python 3.11)

Python Help
1

Hello, one question.

I have an abstract class like this:

from abc import ABCMeta, abstractmethod
from copy import deepcopy

class BookPrototype(metaclass=ABCMeta):

    @property
    def title(self):
        pass

    @title.setter
    @abstractmethod
    def title(self, val):
        pass

    @abstractmethod
    def clone(self):
        pass

Another class implements the setter and the clone methods:

class ScienceFiction(BookPrototype):

    def title(self, val):
        self.title = val

    def __init__(self):
       pass

    def clone(self):
        return deepcopy(self)

The docs states I should decorate the title in the concrete class with: @BookPrototype.title.setter

but when I add it, I get the following error:

TypeError: 'NoneType' object is not callable

If I remove it, the code (apparently) works.

What am I doing wrong?