returns status code <code>399</code>, H2O delegates the request to the next handler while preserving the headers emitted by the handler.
The feature can be used to add extra headers to the response.
</p>
<p>
For example, the following example sets <code>cache-control</code> header for requests against <code>.css</code> and <code>.js</code> files.
</p>

<div class="example">
<div class="caption">Example. Setting cache-control header for certain types of files</div>
<pre><code>paths:
  &quot;/&quot;:
    mrub