code: public function createMetaModel(CreateMetaModelEvent $event)
      {
          if ($event->getMetaModel() !== null) {
              return;
          }
  
          if (isset($this->instancesByTable[$event->getMetaModelName()])) {
              $event->setMetaModel($this->instancesByTable[$event->getMetaModelName()]);
  
              return;
          }
  
          $table = $this
              ->database
              ->createQueryBuilder()
              ->select('*')
              ->from('tl_metamodel')
              ->where('tableName=:tableName')
              ->setParameter('tableName', $event->getMetaModelName())
              ->setMaxResults(1)
              ->execute()
              ->fetch(\PDO::FETCH_ASSOC);
  
          if ($table) {
              $table['system_columns'] = $this->systemColumns;
  
              $this->createInstance($event, $table);
          }
      }
docs: Create a MetaModel instance.
  
  @param CreateMetaModelEvent $event The event.
  
  @return void