How do I know when my cheesecake is finished cooking?

I helped my little sister make a chocolate chip cheesecake and it’s been baking for about half an hour. How do I know if it is cooked in the middle? I know the cookie top is done because it’s brown and looks like how a cookie is supposed to, but I can’t do the clean knife test for the middle because it’s cheesecake… so how do I know when it’s done?