Import::isDefaultValue

protected function isDefaultValue(string $fieldName, $fieldValue): bool
{
	$defaultValue = $this->item->getDefaultValue($fieldName);
	if (is_scalar($fieldValue) && is_scalar($defaultValue))
	{
		return $defaultValue == $fieldValue;
	}
	if ($fieldValue instanceof Date && $defaultValue instanceof Date)
	{
		return (abs($defaultValue->getTimestamp() - $fieldValue->getTimestamp()) <= 1); // allow 1 second difference to avoid "seconds jumping"
	}
	// @todo support compare values of multiple field, if become necessary

	return false;
}