public static function get_instance(WPCF7_ContactForm $contact_form = null)
{
if (empty(self::$instance)) {
if (null == $contact_form) {
return null;
}
self::$instance = new self();
self::$instance->contact_form = $contact_form;
self::$instance->skip_mail = $contact_form->in_demo_mode();
self::$instance->setup_posted_data();
self::$instance->submit();
} elseif (null != $contact_form) {
return null;
}
return self::$instance;
}