public static function getInstance(LoggerInterface $logger = null)
 {
     if (is_null(self::$instance)) {
         $instance = new ServiceFacade();
         $instance->setService(new NavitiaService());
         self::$instance = $instance;
     }
     if (!is_null($logger)) {
         self::$instance->setLogger($logger);
     }
     return self::$instance;
 }
 protected function setUp()
 {
     $this->logger = new Logger('test');
     $this->service = ServiceFacade::getInstance($this->logger);
     $this->formats = array('json', 'object', 'xml');
     $this->config = array('url' => 'http://navitia2-ws.ctp.dev.canaltp.fr', 'version' => 'v1', 'token' => Environment::getNavitiaToken());
 }