1.What does the #[cfg(test)] attribute on a mod tests { ... } block accomplish?
2.In Rust, how does an assertion like assert_eq!(left, right) report a failure?
3.How does each .rs file placed under the tests/ directory relate to your crate?
4.What does the command cargo test it_works do?
5.Why would you place unit tests inside a mod tests block in the same file as the code rather than in the tests/ directory?
Answer every question to submit.