Prevent parent notification to resizables upon resize notification request

[Pickachu]

As the doc reads:

    /**
     * This method can be overridden to filter nested elements that should or
     * should not be notified by the current element. Return true if an element
     * should be notified, or false if it should not be notified.
     ***/

    resizerShouldNotify: function(element) { return true; }

So when overriding this method, the parent should not notify it's descendants about resizes right?

But here, when a child request resizes notifications it is immediatily notified by parent:

https://github.com/PolymerElements/iron-resizable-behavior/blob/master/iron-resizable-behavior.html#L170

_onIronRequestResizeNotifications: function(event) {
       ...
      this._notifyDescendant(target);
}

Am I missing something here? Is the resizerShouldNotify method only for notifications after the request? Or this is a bug? If not, how should I proceed to avoid children notifications upon request?

Thanks for the great behavior, have a smart cat!