iirc this class in nearly not used. It should not be in Zend/Mvc namespace (rather in ServiceManager). The issue with this class is that it does not allow to fetch config from the service locator Config.

We already had a talk about that, but to make this class useful, I'd suggest something like:

```php
const PLUGIN_PATH_CONFIG = ''; // for instance 'zfr_rest.data'

public function createService()
{
    $config = $serviceLocator->get('Config');
    foreach (explode('.', self::PLUGIN_PATH_CONFIG) as $value) {
        $config = $config[$value];
    }

    return new $pluginManagerClass(new $pluginConfigClass($config));
}
```

This, way creating a new plugin factory just needs to override the PLUGIN_PATH_CONFIG (in most cases).