protected function fetchObjectFromPersistence($identity, $targetType)
{
if ($targetType === Thumbnail::class) {
$object = $this->persistenceManager->getObjectByIdentifier($identity, $targetType);
} elseif (is_string($identity)) {
$object = $this->assetRepository->findByIdentifier($identity);
} else {
throw new InvalidSourceException('The identity property "' . $identity . '" is not a string.', 1415817618);
}
return $object;
}