Documentation
pub mod outermost {
    pub fn middle_function() {

    }

    pub fn middle_secret_function() {}

    pub mod inside {
        pub fn inner_function() {
        }

        pub fn secret_function() {}
    }
}

/// # Examples
/// 
/// ```
/// let value = "this value";
/// ```
/// works
fn try_me() {
    outermost::middle_function();
    outermost::middle_secret_function();
    outermost::inside::inner_function();
    outermost::inside::secret_function();
}