public function inlineCss($file)
    {
        $collection = $this->collection();
        if (!$collection->contains($file)) {
            throw new RuntimeException('Cannot create a stylesheet for a build that does not exist.');
        }
        $compiler = $this->factory()->compiler();
        $results = $compiler->generate($collection->get($file));

        return $this->Html->tag('style', $results, ['type' => 'text/css']);
    }