protected function addServiceAlias($alias, $id)
    {
        $name = sfServiceContainer::camelize($alias);
        return <<<EOF

  protected function get{$name}Service()
  {
    return {$this->getServiceCall($id)};
  }

EOF;
    }
 protected function getServiceCall($id)
 {
     if ('service_container' == $id) {
         return '$this';
     }
     if ($this->container->hasServiceDefinition($id)) {
         return sprintf('$this->get%sService()', sfServiceContainer::camelize($id));
     }
     return sprintf('$this->getService(\'%s\')', $id);
 }