Pool.release defined but not implemented #168

The function release() is defined in the Pool class

But there is no release function in the implementation pool.js
https://github.com/CodeFoodPixels/node-promise-mysql/blob/7c075145cc981ae945ee612181e28b2c74f3e843/lib/pool.js

Is it a mistake to have it in the definition? Or is it missed to be implemented?

For example Visual Studio Code will give the release function as an autocomplete suggestion. But if you use it you will get the error TypeError: _a.release is not a function