Your project should not use invalid return types

More information: https://insight.symfony.com/what-we-analyse/php.invalid_return_typehint

in src/Container.php, line 93 
  1.      * @return EventDispatcherInterface
  2.      */
  3.     final public function getEventDispatcher(): EventDispatcherInterface
  4.     {
  5.         if (isset($this->handledEntries[EventDispatcherInterface::class])) {
  6.             return $this->handledEntries[EventDispatcherInterface::class];
    Method Projek\Container::getEventDispatcher() should return Psr\EventDispatcher\EventDispatcherInterface but returns mixed.
    Time to fix: about 9 minutes
    Read doc Permalink Copy Prompt
    
                                    Last edited  by Fery Wardiyanto
                    
  7.         }
  9.         if (! $this->entries->offsetExists(EventDispatcherInterface::class)) {
  10.             // Simplest implementation to keep core hooks (like ContainerAware) working.
  11.             $this->entries->offsetSet(