pub trait Trackable {
// Required methods
fn track_id(&self) -> String;
fn track_method(&self) -> String;
fn track_payload(&self) -> String;
fn track_from(&self) -> String;
fn track_to(&self) -> String;
fn track(&self) -> bool;
// Provided methods
fn track_payload_fmt(&self) -> String { ... }
fn track_key_fmt(&self) -> String { ... }
fn track_fmt(&self, tracker: &Tracker) -> String { ... }
}