Это вызывает ошибку, когда я пытаюсь умножить 2 объекта дроби..кто-нибудь поможет?

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from fractions import gcd


class Fraction:
    def __init__(self,numerator,denominator):
        assert denominator != 0, "nenner muß nicht null sein"
        if denominator < 0:
            (numerator,denominator) = (-numerator,-denominator)
        gcden = gcd(numerator,denominator)
        self.__num = numerator // gcden
        self.__den = denominator // gcden
    @property
    def numerator(self):
        return self.__num
    @property
    def denominator(self):
        return self.__den

    def __mult__(self,other):
        new_num = self.numerator * other.numerator
        new_den = self.denominator * other.denominator
        return Fraction(new_num,new_den)


f1 = Fraction(2,6)
f2 = Fraction(5,25)


f3 = f1 * f2 

if __name__ == '__main__':
    print(f1.numerator,f1.denominator)
    print(f2.numerator,f2.denominator)
    print('------')
    print(f3.numerator,f3.denominator)

это порождает ошибку

gcden = gcd(numerator,denominator)
Traceback (most recent call last):
  File "zwölf.py", line 127, in <module>
    f3 = f1 * f2 
TypeError: unsupported operand type(s) for *: 'Fraction' and 'Fraction'

Что я уже пробовал:

if __name__ == '__main__':
    print(f1.numerator,f1.denominator)
    print(f2.numerator,f2.denominator)
    print('------')
    print(f3.numerator,f3.denominator)

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