class \Symfony\Component\DependencyInjection\ParameterBag\EnvPlaceholderParameterBag extends \Symfony\Component\DependencyInjection\ParameterBag\ParameterBag
class \Symfony\Component\DependencyInjection\Compiler\MergeExtensionConfigurationParameterBag extends \Symfony\Component\DependencyInjection\ParameterBag\EnvPlaceholderParameterBag
class \Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag extends \Symfony\Component\DependencyInjection\ParameterBag\ParameterBag