Accordion Event on Open/Close

Is your feature request related to a problem? Please describe:

Layouts resize based on accordion open and closing. I would expect a layout to return to the size it was previously before accordion item opened (Maybe a feature in the future), however this can be achieved with events on accordion open and close.

Is it possible to construct a solution with the existing API?

I do not believe it's possible to perform on existing API.

Describe the solution you'd like to see:

Similar to Check widget, implement an OnChange and boolean of opened.