get_president_inside_bunker() assert president_is_inside_bunker() close_bunker_doors() assert bunker_doors_are_closed() send_nukes() With asser

get_president_inside_bunker() assert president_is_inside_bunker() close_bunker_doors() assert bunker_doors_are_closed() send_nukes() With asserts enabled this is fine. With asserts disabled you might start sending nukes while the president is still outside or the doors to the bunker are still open.