/**
* Constructor and getter for the singleton instance
* @return instance of $config->userHookClass
*/
static function singleton()
{
if (self::$_singleton == null) {
$config = CRM_Core_Config::singleton();
$class = $config->userHookClass;
require_once str_replace('_', DIRECTORY_SEPARATOR, $config->userHookClass) . '.php';
self::$_singleton = new $class();
}
return self::$_singleton;
}
