Multifield::transformToExternalValue

public function transformToExternalValue(string $commonFieldName, $value, int $valuesType)
{
	if (!($value instanceof Collection))
	{
		throw new ArgumentTypeException('value', Collection::class);
	}

	if ($valuesType === Values::ACTUAL)
	{
		return $value->toArray();
	}

	$current = $value;

	$comparer = new MultifieldComparer();

	return $comparer->getChangedCompatibleArray($this->remindActual($commonFieldName), $current);
}