A few software design patterns are seamlessly integrated into Rust, so we're using them without realizing them. Which is great! A hint: it is 2 creational patterns.

A typical Mediator implementation in other languages is a classic anti-pattern in Rust: many objects hold mutable cross-references on each other, trying to mutate each other, which is a deadly sin in Rust - the compiler won't pass your first naive implementation unless it's oversimplified.