protected function modifyMultivaluedAttribute(array $values, array $newValues)
    {
        if ($this->getOperationType() == AttributeConverterInterface::TYPE_CREATE || ($this->getBatch() && $this->getBatch()->isTypeAdd())) {
            $values = array_merge($values, $newValues);
        } elseif ($this->getBatch() && $this->getBatch()->isTypeReplace()) {
            $values = $newValues;
        } elseif ($this->getBatch() && $this->getBatch()->isTypeRemove()) {
            $values = array_diff($values, $newValues);
        }

        return $values;
    }