Check out new pull request to 2.1.1 branch, I renamed check() method back (for backward compatibility), but set() method is now protected and is intended only to implement provider-specific setter job, it doesn't check for lock existance as prior. I think it was not correct, because it's code was almost duplicated in all providers and it should be compliant to get() method in declaration. Currently there is a new method run(), which is the only public and is called by daemon to execute main plugin logic (as in other plugins). Currently if one wrote additional lock plugins - they should continue to work, because check() method does the same as priorily, just a double-check may happen (inside run() and then inside user-defined set() method)