WOOF :: mixin()
A powerful method allowing developers to augment the classes in MEOW and WOOF with their own class functions, without needing to create class extensions of them. Classes are augmented by defining another class with public static functions each with the first argument being the object that the method will be applied on, followed by any arguments you’d like to be able to pass to the method at call time.
Important Note: you should always wrap any mixin definitions in an if test that checks whether the WOOF class exists, since attempts to call the mixin methods may fail when WOOF is not available – this can happen in a number of circumstances, particularly when deactivating or updating plugins. See the example below for the correct way to do this.