-// Rust-101, Part 11: Trait Objects, Box, Rc
-// =========================================
+// Rust-101, Part 11: Trait Objects, Box, Rc, Lifetime bounds
+// ==========================================================
//@ We will play around with closures a bit more. Let us implement some kind of generic "callback"
//@ mechanism, providing two functions: Registering a new callback, and calling all registered callbacks. There will be two