: str_replace(): Passing null to parameter #2 ($replace) of type array|string is deprecated in
namespace Yoast\WP\SEO\Models;
* Abstract class for indexable extensions.
abstract class Indexable_Extension extends Model {
* Holds the Indexable instance.
protected $indexable = null;
* Returns the indexable this extension belongs to.
* @return Indexable The indexable.
public function indexable() {
if ( $this->indexable === null ) {
$this->indexable = $this->belongs_to( 'Indexable', 'indexable_id', 'id' )->find_one();