protected function render()
    {
        $this->display('* Rendering documents');
        foreach ($this->documents as $file => &$document) {
            $this->display(' -> Rendering '.$file.'...');
            $target = $this->getTargetOf($file);

            $directory = dirname($target);
            if (!is_dir($directory)) {
                mkdir($directory, 0755, true);
            }

            file_put_contents($target, $document->renderDocument());
        }
    }