code: public function getServiceContainer()
      {
          if (!$this->serviceContainer) {
              $this->useDefaultServiceContainer();
          }
          if (is_callable($this->serviceContainer)) {
              return $this->serviceContainer = $this->serviceContainer->__invoke();
          }
  
          return $this->serviceContainer;
      }
docs: Retrieve the service container in use.
  
  @return IMetaModelsServiceContainer|null
  
  @deprecated The service container will get removed, use the symfony service container instead.