517     locked_keys: Mutex<HashSet<i64>>,  field
529         Self { locked_keys: Mutex::new(HashSet::new()), cond_var: Condvar::new() }  in new()
536         let mut locked_keys = self.locked_keys.lock().unwrap();  in get()  localVariable
537         while locked_keys.contains(&key_id) {  in get()
538             locked_keys = self.cond_var.wait(locked_keys).unwrap();  in get()
540         locked_keys.insert(key_id);  in get()
549         let mut locked_keys = self.locked_keys.lock().unwrap();  in try_get()  localVariable
550         if locked_keys.insert(key_id) {  in try_get()
567         let mut locked_keys = KEY_ID_LOCK.locked_keys.lock().unwrap();  in drop()  localVariable
568         locked_keys.remove(&self.0);  in drop()
569         drop(locked_keys);  in drop()