function testNotificationMissingPasswordThrows()
 {
     $postData = $this->schemaNotification('transaction_notification.json');
     Config::set('username', '', Config::ENV_SANDBOX);
     $this->assertEqual('', Config::getPassword());
     try {
         Transaction::notification($postData);
         $this->fail('Errors\\ArgumentError expected!');
     } catch (Errors\ArgumentError $exe) {
         $this->assertEqual('password is not configured! See Hypercharge\\Config::set()', $exe->getMessage());
         return;
     } catch (Exception $exe) {
         $this->fail('unexpected Exception: ' . $exe->toString());
     }
 }