Can't pass test 21.

Hello, all!

My solution fails at test 21

army_1 = Army()
army_2 = Army()
army_1.add_units(Lancer, 7)
army_1.add_units(Vampire, 3)
army_1.add_units(Healer, 1)
army_1.add_units(Warrior, 4)
army_1.add_units(Healer, 1)
army_1.add_units(Defender, 2)
army_2.add_units(Warrior, 4)
army_2.add_units(Defender, 4)
army_2.add_units(Healer, 1)
army_2.add_units(Vampire, 6)
army_2.add_units(Lancer, 4)
battle = Battle()
battle.straight_fight(army_1, army_2)

Your result: true Right result: false

This message is nowhere near enough to understand what exactly is going wrong. I've tried to understand where is the problem, but it's not something obvious as long as I passed all the previous tests. Has anyone faced the same issue? I think it would be a lot more informative if we were provided with health of every unit in every army after the battle than just simple True or False.