I'm about to lose my temper! Why is my code failing!!!

import random


class Die:
    def __init__(self, sides=2):
        if sides < 2:
            raise ValueError("Can't have fewer than two sides")
        self.sides = sides
        self.value = random.randint(1, sides)

    def __int__(self):
        return self.value

    def __add__(self, other):
        return int(self) + other

    def __radd__(self, other):
        return self + other

class Hand(list):
    def __init__(self, size = 0, die_class = D20):
        super().__init__()
        for _ in range(size):
            self.append(die_class())
        #self.sort()

    @classmethod
    def roll(cls, size):
        return cls(size, die_class = D20)

    @property 
    def total(self):
        self.sort()
        return sum(self)

class Hand(list):
    @property
    def total(self):
        return sum(self)