src/Bootstrap.php
private function createKernel()
    {
        $debug = $this->getDebug();
        $environment = $this->getEnvironment();
        $rootDirectory = $this->getRootDirectory();

        $configLoaderFactory = new ConfigLoaderFactory($rootDirectory, $environment);
        $configLoader = $configLoaderFactory->create();

        $kernelFactory = new AppKernelFactory($configLoader, $environment, $debug);

        return $kernelFactory->create();
    }
private function createKernel()
    {
        $debug = $this->getDebug();
        $environment = $this->getEnvironment();
        $rootDirectory = $this->getRootDirectory();

        $configLoaderFactory = new ConfigLoaderFactory($rootDirectory, $environment);
        $configLoader = $configLoaderFactory->create();

        $kernelFactory = new AppKernelFactory($configLoader, $environment, $debug);

        return $kernelFactory->create();
    }
@return AppKernel

@throws \InvalidArgumentException
@throws \UnexpectedValueException
@throws \RuntimeException