<ul>
<li>$oldValue: prior cache value or false if none was present</li>
<li>&amp;$ttl: alterable reference to the TTL to be assigned to the new value</li>
<li>&amp;$setOpts: alterable reference to the <a class="el" href="classWANObjectCache.html#aa1eb038eb185a1c98fd58f5ab0479f3b" title="Set the value of a key in cache.">set()</a> options to be used with the new value</li>
<li><dl class="section rcs"><dt>oldAsOf</dt><dd>generation UNIX timestamp of </dd></dl>
oldValue or null if not present (since 1.28)</li>
<li><dl class="section rcs"><dt>params</dt><dd>custom field/value map as defined by </dd></dl>
cbParams (since 1.35)</li>
</ul>

/**
 *   - $oldValue: prior cache value or false if none was present
 *   - &$ttl: alterable reference to the TTL to be assigned to the new value
 *   - &$setOpts: alterable reference to the set() options to be used with the new value
 *   - $oldAsOf: generation UNIX timestamp of $oldValue or null if not present (since 1.28)
 *   - $params: custom field/value map as defined by $cbParams (since 1.35)
 */