/**
* Find a volume by an ISBN.
*
* @param string $isbn
* @return Volume|null
*/
public function findByISBN($isbn)
{
/** @var VolumeSearchQuery $query */
$query = new VolumeSearchQuery();
$query->setIsbn($isbn);
$volumes = $this->lookup($query);
if ($volumes->getTotalItems()) {
return $volumes->getItems()[0];
}
return null;
}
