* Posts that are created on this system are using System::createUUID.
* Received ActivityPub posts are using Processor::getGUIDByURL.
*
- * @param string $uri uri of an item entry
- * @param string $host hostname for the GUID prefix
- * @return string unique guid
+ * @param string $uri uri of an item entry
+ * @param string|null $host hostname for the GUID prefix
+ * @return string Unique guid
*/
- public static function guidFromUri(string $uri, string $host): string
+ public static function guidFromUri(string $uri, string $host = null): string
{
// Our regular guid routine is using this kind of prefix as well
// We have to avoid that different routines could accidentally create the same value