'When Mario becomes small, converts all mushroom powerups to
fireflower powerups'

def convert_fireflowers_to_mushrooms(self):

    for brick in self.brick_group:
        if (brick.contents == c.FIREFLOWER):
            brick.contents = c.MUSHROOM
    for coin_box in self.coin_box_group:
        if (coin_box.contents == c.FIREFLOWER):
            coin_box.contents = c.MUSHROOM
