/**
* @param string $pluginClass
*/
public static function addPlugin($pluginClass)
{
self::getPluginInstances();
$plugin = new $pluginClass();
$pluginName = $plugin->getPluginName();
self::$plugins[$pluginName] = $pluginClass;
self::$pluginInstances[$pluginName] = $plugin;
self::$useCache = false;
// disable the cache so that the added plugin will have effect
}
