Frontend\Core\Engine\Page::processExtras PHP Method

    protected function processExtras()
    {
        // loop all extras
        foreach ($this->extras as $extra) {
            $this->getContainer()->get('logger')->info('Executing ' . get_class($extra) . " '{$extra->getAction()}' for module '{$extra->getModule()}'.");
            // all extras extend FrontendBaseObject, which extends KernelLoader
            $extra->setKernel($this->getKernel());
            // overwrite the template
            if (is_callable(array($extra, 'getOverwrite')) && $extra->getOverwrite()) {
                $this->templatePath = $extra->getTemplatePath();
            }
        }
    }