private function getOrCreateDefinition()
    {
        if ($this->container->hasDefinition(Contao2BackendViewDefinitionInterface::NAME)) {
            $view = $this->container->getDefinition(Contao2BackendViewDefinitionInterface::NAME);
            if (!$view instanceof Contao2BackendViewDefinitionInterface) {
                throw new DcGeneralInvalidArgumentException(
                    'Configured BackendViewDefinition does not implement Contao2BackendViewDefinitionInterface.'
                );
            }
            return $view;
        }
        $this->container->setDefinition(
            Contao2BackendViewDefinitionInterface::NAME,
            $view = new Contao2BackendViewDefinition()
        );

        return $view;
    }