public function get_attendees_by_order_id( $order_id, $ticket_id = null ) {
		if ( ! is_numeric( $order_id ) ) {
			return parent::get_attendees_by_order_id( $order_id, $ticket_id );
		}

		$find_by_args = [
			'post_id'        => $order_id,
			'ticket_id'      => [],
			'posts_per_page' => 1,
		];

		if ( $ticket_id ) {
			$find_by_args['ticket_id'] = (array) $ticket_id;
		}

		$orders = Tribe__Tickets__Commerce__PayPal__Order::find_by(
			$find_by_args,
			[
				// Get just the paypal ID var we need.
				'txn_id',
			]
		);

		if ( ! $orders ) {
			return [];
		}

		$order_id = current( $orders )->paypal_id();

		return parent::get_attendees_by_order_id( $order_id, $ticket_id );
	}