549     locked_keys: Mutex<HashSet<i64>>,  field
561         Self { locked_keys: Mutex::new(HashSet::new()), cond_var: Condvar::new() }  in new()
568         let mut locked_keys = self.locked_keys.lock().unwrap();  in get()  localVariable
569         while locked_keys.contains(&key_id) {  in get()
570             locked_keys = self.cond_var.wait(locked_keys).unwrap();  in get()
572         locked_keys.insert(key_id);  in get()
581         let mut locked_keys = self.locked_keys.lock().unwrap();  in try_get()  localVariable
582         if locked_keys.insert(key_id) {  in try_get()
599         let mut locked_keys = KEY_ID_LOCK.locked_keys.lock().unwrap();  in drop()  localVariable
600         locked_keys.remove(&self.0);  in drop()
601         drop(locked_keys);  in drop()