Get header data from a request response in swift : <p>I want to get X-Dem-Auth in a header request with swift to stock that in my app.</p>

<p>See the response :</p>

<pre><code>headers {
    "Content-Length" = 95;
        "Content-Type" = "application/json; charset=utf-8";
        Date = "Fri, 15 Apr 2016 08:01:58 GMT";
        Server = "Apache/2.4.18 (Unix)";
        "X-Dem-Auth" = null;
        "X-Powered-By" = Express;
</code></pre>
