docs: def release(self, key, owner):
          """Release lock with given name.
            `key` - lock name
            `owner` - name of application/component/whatever which held a lock
          Raises `MongoLockException` if no such a lock.
          """
          status = self.collection.find_and_modify(
              {'_id': key, 'owner': owner},
              {'locked': False, 'owner': None, 'created': None, 'expire': None}
          )