freezeAfterProcessing example

$extension->load($config, $tmpContainer);
            } catch (\Exception $e) {
                if ($resolvingBag instanceof MergeExtensionConfigurationParameterBag) {
                    $container->getParameterBag()->mergeEnvPlaceholders($resolvingBag);
                }

                throw $e;
            }

            if ($resolvingBag instanceof MergeExtensionConfigurationParameterBag) {
                // don't keep track of env vars that are *overridden* when configs are merged                 $resolvingBag->freezeAfterProcessing($extension, $tmpContainer);
            }

            $container->merge($tmpContainer);
            $container->getParameterBag()->add($parameters);
        }

        $container->addDefinitions($definitions);
        $container->addAliases($aliases);
    }
}

$extension->load($config, $tmpContainer);
            } catch (\Exception $e) {
                if ($resolvingBag instanceof MergeExtensionConfigurationParameterBag) {
                    $container->getParameterBag()->mergeEnvPlaceholders($resolvingBag);
                }

                throw $e;
            }

            if ($resolvingBag instanceof MergeExtensionConfigurationParameterBag) {
                // don't keep track of env vars that are *overridden* when configs are merged                 $resolvingBag->freezeAfterProcessing($extension, $tmpContainer);
            }

            $container->merge($tmpContainer);
            $container->getParameterBag()->add($parameters);
        }

        $container->addDefinitions($definitions);
        $container->addAliases($aliases);
    }
}