Just by accident i found this in CLogRouter when i studied the framework code:
public function setRoutes($config)
{
$routes=$this->getRoutes();
foreach($config as $c)
{
if(isset($c['class']))
$this->_routeConfig[]=new CConfiguration($c);
else
throw new CException(Yii::t('yii','Log route configuration must have a "class" value.'));
}
}
$routes is never used?!