pub trait ThreadSafeCachePersistTrait<K: 'static + Clone + Eq + Hash + Serialize + DeserializeOwned, V: Clone + Serialize + DeserializeOwned + 'static>: ThreadSafeCacheTrait<K, V> {
// Required methods
fn save(&mut self, file_name: &str);
fn load(&mut self, file_name: &str);
}