[E010] Error: standalone type `never` cannot be used in a union
   ,-[code.php:3:17]
   |
 3 | function foo(): never|string {
   *                 ^^|^^^  
   *                   `----- try using a type other than `never`
   *                         
   *                          
   * 
   * Note: `never`, `void`, `mixed`, and nullable types cannot be used in a union
---'