You can modify the container here before it is dumped to PHP code.
@api
ContainerBuilder $container:
Overrides MergeExtensionConfigurationPass::process
public function process(ContainerBuilder $container) {
foreach ($this->extensions as $extension) {
if (!count($container
->getExtensionConfig($extension))) {
$container
->loadFromExtension($extension, array());
}
}
parent::process($container);
}