"Attack Yourself" Feature

What if you could "attack yourself"?
You wouldn't do any real damage, it would just be a simulated attack.
If we had this feature we could see how we would fare against someone who would attack us.
You could have your normal troop capacity and the choice of any troops that you have.
Plus it could help you train for attacks.
There would be no benefits to this other than practice and knowledge, you wouldn't get XP or gain trophies or anything, this feature would simply be for practice and help with your base.