| $ cargo run | |
| Compiling cons-list v0.1.0 (file:///projects/cons-list) | |
| Finished dev [unoptimized + debuginfo] target(s) in 0.63s | |
| Running `target/debug/cons-list` | |
| a after = Cons(RefCell { value: 15 }, Nil) | |
| b after = Cons(RefCell { value: 6 }, Cons(RefCell { value: 15 }, Nil)) | |
| c after = Cons(RefCell { value: 10 }, Cons(RefCell { value: 15 }, Nil)) |