    prob = models.FloatField(default=0.0)
    manual = models.BooleanField(default=False)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        abstract = True


class Category(Label):
    objects = CategoryManager()
    example = models.ForeignKey(
        to=Example,