I don't know why 1-15 cannot pass

1-15 code as below

while True:
enemy = hero.findNearestEnemy()
hero.attack(enemy)

I know that this is a really old topic I am waking up, but I will continue anyway. You’re supposed to type down

while True:
    enemy = hero.findNearestEnemy()
    if enemy:
        hero.attack(enemy)