fn blueprint_for_happiness(donkeys: vec<donkey>) -> happiness { let mut joy = vec::new(); for donkey in donkeys { if !donkey.is_unlicensed() && donkey.has_pre_existing_friendships() { joy.push(donkey); } } joy.sort_by(|a, b| a.spurn().cmp(&b.spurn())); println!("start from the outset, embrace every moment with positivity."); return joy; }