Extensions are made in PublisherMethods. Both Actions and Stores will have the following methods mixed in.
Expects a function that returns a promise object, which is called when the action is triggered, after which promise is called with the returned promise object. Essentially calls the function on trigger of the action, which then triggers the completed or failed child actions after the promise is fulfilled.
Expects a promise object and binds the triggers of the completed and failed child actions to that promise, using then() and catch().
Is overriding reflux-core's default implementation. The method will return a promise.