doesnt pass but says "does your 'dragon' class extend monster"

import random

COLORS = ['yellow', 'red', 'blue', 'green']


class Monster:
    min_hit_points = 1
    max_hit_points = 1
    min_experience = 1
    max_experience = 1
    weapon = 'sword'
    sound = 'roar'

    def __init__(self, **kwargs):
        self.hit_points = random.randint(self.min_hit_points, self.max_hit_points)
        self.experience = random.randint(self.min_experience, self.max_experience)
        self.color = random.choice(COLORS)

        for key, value in kwargs.items():
            setattr(self, key, value)

    def battlecry(self):
        return self.sound.upper()

# passing the Monster class inside of parentheses, tells Python that Goblin is a subclass of monster, which means Goblin has all the attrs of Monsters unless modified within Goblinclass Goblin(Monster): 
    max_hit_points = 3
    max_experience = 2
    sound = 'squeak'

class Troll(Monster):
    min_hit_points = 3
    max_hit_points = 5
    min_experience = 2
    max_experience = 6
    sound = 'growl'
class Dragon(Monster):
    min_hit_points = 5
    max_hit_points = 10
    min_experience = 6
    max_experience = 10
    sound = 'raaaaaaaaaaaar'