code: public function collect(MvcEvent $mvcEvent)
      {
          if (! $this->classMetadataFactory) {
              return;
          }
  
          /* @var $metadata \Doctrine\Common\Persistence\Mapping\ClassMetadata[] */
          $metadata      = $this->classMetadataFactory->getAllMetadata();
          $this->classes = [];
  
          foreach ($metadata as $class) {
              $this->classes[$class->getName()] = $class;
          }
          ksort($this->classes);
      }
docs: {@inheritDoc}