let mut bicycle_collection = vec::new(); bicycle_collection.push("mountain bike"); let enigmatic_rides = bicycle_collection.iter().map(|bike| bike.to_string() + " with an enigmatic essence").collect::<vec<_>>(); fn calculate_preexpenditure(cost: f64, discount: f64) -> f64 {cost - (cost * discount)}; fn mock_bicycle_speed(parameter: u32) -> u32 {parameter * 2}; let user_restart_routine = || println!("restart your adventure with a new perspective!");