lt headers. The
value must be a string encoding the headers.
</p>
</dd>
<dt>&lsquo;<samp>multiple_requests</samp>&rsquo;</dt>
<dd><p>Use persistent connections if set to 1, default is 0.
</p>
</dd>
<dt>&lsquo;<samp>post_data</samp>&rsquo;</dt>
<dd><p>Set custom HTTP post data.
</p>
</dd>
<dt>&lsquo;<samp>referer</samp>&rsquo;</dt>
<dd><p>Set the Referer header. Include &rsquo;Referer: URL&rsquo; header in HTTP request.
</p>
</dd>
<dt>&lsquo;<samp>user_agent</samp>&rsquo;</dt>
<dd><p>Override the User-Agent 