Botman PHP 7.2.4 opcache

I am tring to get a simple conversation working and the response fails, I need to know how to use opcache with botman and php 7.2.4 - WAMP

I have modified the php.ini file adding the zend_extension setting, following the documentation I have use:

use BotMan\BotMan\Cache\DoctrineCache;

$botman = BotManFactory::create($config, new DoctrineCache($doctrineCacheDriver));

This gives and undefined variable: doctrineCacheDriver error

The function uses a $driver variable, is there additional settings that need to be configured.

Any help setting up cache, php 7 on wamp, would be much appreciated.