/**
* Adds a sort directive to this search query.
*
* If no sort is manually set, the results will be sorted descending by
* relevance.
*
* @param string $field
* The field to sort by. The special fields 'search_api_relevance' (sort by
* relevance) and 'search_api_id' (sort by item id) may be used.
* @param string $order
* The order to sort items in - either 'ASC' or 'DESC'.
*
* @return $this
*
* @throws \Drupal\search_api\SearchApiException
* Thrown if the field is multi-valued or of a fulltext type.
*
* @see \Drupal\search_api\Query\QueryInterface::sort()
*/
public function sort($field, $order = 'ASC')
{
if (!$this->shouldAbort()) {
$this->query->sort($field, $order);
}
return $this;
}