Toolbar::processButtonRender

protected function processButtonRender(Button $button)
{
	$shouldAddThemeModifier = (bool)array_intersect($button->getClassList(), [
		'ui-btn-light-border',
		'ui-btn-light',
		'ui-btn-link',
	]);

	if ($shouldAddThemeModifier)
	{
		$button->addClass('ui-btn-themes');
	}

	return $button->render(false);
}