src/Kernel.php
protected function boot()
    {
        if ($this->hasBooted()) return; // Nothing to do

        if ($this->debug) {
            $this->setContainer(new ContainerBuilder(new EnvPlaceholderParameterBag($this->getContainerParameters())));
            $this->loadContainerConfiguration();
            $this->container->compile(true);
        } else {
            $filename = $this->getContainerCacheFilename();

            if (file_exists($filename)) {
                require_once($filename);
                $this->setContainer(new CachedContainer());
            } else {
                $this->setContainer(new ContainerBuilder(new EnvPlaceholderParameterBag($this->getContainerParameters())));
                $this->loadContainerConfiguration();
                $this->container->compile(true);

                if ($this->containerIsCacheable()) {
                    $dumper = new PhpDumper($this->container);
                    file_put_contents($filename, $dumper->dump());
                }
            }
        }
    }
protected function boot()
    {
        if ($this->hasBooted()) return; // Nothing to do

        if ($this->debug) {
            $this->setContainer(new ContainerBuilder(new EnvPlaceholderParameterBag($this->getContainerParameters())));
            $this->loadContainerConfiguration();
            $this->container->compile(true);
        } else {
            $filename = $this->getContainerCacheFilename();

            if (file_exists($filename)) {
                require_once($filename);
                $this->setContainer(new CachedContainer());
            } else {
                $this->setContainer(new ContainerBuilder(new EnvPlaceholderParameterBag($this->getContainerParameters())));
                $this->loadContainerConfiguration();
                $this->container->compile(true);

                if ($this->containerIsCacheable()) {
                    $dumper = new PhpDumper($this->container);
                    file_put_contents($filename, $dumper->dump());
                }
            }
        }
    }
Creates a container instance