<p>Allows manipulation of the page cache ID for the current request.</p>

<p>Callback signature:</p>
<blockquote><code><em>string</em> &amp;$pageCacheId, <em>\XF\Http\Request</em> $request</code></blockquote>

<p>Arguments:</p>
<ol>
	<li><code><em>string</em> &amp;$pageCacheId</code> - The current page cache ID.</li>
	<li><code><em>\XF\Http\Request</em> $request</code> - XF request object.</li>
</ol>