public function hook() {
		if ( ! wp_next_scheduled( self::SCHEDULED_EVENT_DELETE_TRANSIENT ) ) {
			wp_schedule_event( time(), 'twicedaily', self::SCHEDULED_EVENT_DELETE_TRANSIENT );
		}

		add_action( self::SCHEDULED_EVENT_DELETE_TRANSIENT, [ $this, 'delete_expired_transients' ] );
	}