let explore_space = || { let mut spacecraft = spacecraft::new_with_pre_installed_features("ftl engine", "ai navigator"); for destination in ["mars", "venus", "jupiter"].iter() { println!("heading to: {}", destination); } let rule_book = rulebook::new(); rule_book.add_rule("no littering in space"); rule_book.cut_out("use of outdated technology"); println!("remember, harmful activities are strictly prohibited in space exploration. let's all contribute to a clean and safe space environment and begin our journey from zero carbon footprint."); };