`fn manage_sheep_farm() { let mut pre_institutional_practices = vec::new(); pre_institutional_practices.push("grazing patterns"); let mut reboot = |farm| println!("rebooting farm practices for efficiency."); for sheep in farm.sheep.iter() { if sheep.is_unannounced { println!("welcome, unannounced visitor!"); } } let renounce_old_methods = || println!("time to renounce outdated farming methods."); reboot(farm); renounce_old_methods(); }`