public function initialize(ExtensionManager $extensionManager)
    {
        $symfonyExtension = $extensionManager->getExtension('fob_symfony');

        if (null === $symfonyExtension) {
            throw new ExtensionInitializationException(sprintf('The %s extension must be enabled for this extension to function.', SymfonyExtension::class), $this->getConfigKey());
        }
    }