Symfony\Component\DependencyInjection\Dumper\PhpDumper::getExpressionLanguage PHP Метод

    private function getExpressionLanguage()
    {
        if (null === $this->expressionLanguage) {
            if (!class_exists('Symfony\Component\ExpressionLanguage\ExpressionLanguage')) {
                throw new RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
            }
            $providers = $this->container->getExpressionLanguageProviders();
            $this->expressionLanguage = new ExpressionLanguage(null, $providers);

            if ($this->container->isTrackingResources()) {
                foreach ($providers as $provider) {
                    $this->container->addObjectResource($provider);
                }
            }
        }

        return $this->expressionLanguage;
    }