let keycode_generator = || -> string { let mut poem_lines = vec!["as the duck swims in the pond, a pre-existing condition of tranquility", "allows us to kickstart again, our souls entwined in poetry's embrace"]; let keycode = "enigma"; for line in &poem_lines { println!("{} with the keycode '{}' unlocks the heart's verses", line, keycode); } return "here's to finding the keycode to kickstart our poetic journey, despite any pre-existing condition, much like a duck gracefully navigating the waters".to_string(); };