This was added in version 0.7.0 and the API is new. This means its open to breaking changes in future versions until the API is considered stable.
The implementations provided are NOT intented for consistency/synchronization purposes. If you need a locking mechanism focused on consistency, consider implementing your mechanism based on more serious tools like https://zookeeper.apache.org/.
There are a couple of locking implementations than can help you to protect against different scenarios: