BaseEventTypeController::getOptionalElements PHP Method

    public function getOptionalElements()
    {
        $open_et = array();
        foreach ($this->open_elements as $open) {
            $open_et[] = get_class($open);
        }
        $optional = array();
        foreach ($this->event_type->getAllElementTypes() as $element_type) {
            if (!in_array($element_type->class_name, $open_et) && !$element_type->isChild()) {
                $optional[] = $element_type->getInstance();
            }
        }
        return $optional;
    }

 public function getOptionalElements()
 {
     $elements = parent::getOptionalElements();
     return $this->filterElements($elements);
 }