Minor Description
I use StatelessForm because I want the page to be stateless with it in most cases but in other cases the page should become stateful.
A StateLessForm with multiple buttons replaces its parent panel at the end of the button's onSubmit().
After onSubmit(), StateLessForm#process() calls getPage() with the result of a RuntimeException "No Page found for component".
Martin Grigorov suggested to use #findPage() instead of #getPage()
Looking at StatelessForm#process(), I guess that a null check of the result of #findPage() may be required.
I don't understand the mechanics of "Remove the page parameters for all form component otherwise they get appended to action URL" so I can't assess the consequences of NOT doing this when a panel that contains the form replaces itself.
I guess it is ok to NOT execute that code in case where the page is gone.