private function checkDeviceType()
    {
        // The 'deviceType' parameter must have been defined.
        if (!isset($this->deviceType)) {
            throw new PushwooshException('The \'deviceType\' property is not set !');
        }

        // The 'deviceType' must be valid
        switch ($this->deviceType) {
            // 1 - iOS
            case 1:
                break;

            // 2 - BlackBerry
            case 2:
                break;

            // 3 - Android
            case 3:
                break;

            // 4 - Nokia ASHA
            case 4:
                break;

            // 5 - Windows Phone
            case 5:
                break;

            // 6 - Error (not documented in the Pushwoosh documentation)
            case 6:
                throw new PushwooshException('The \'deviceType\' value \'' . $this->deviceType . '\' is invalid !');
                break;

            // 7 - Mac OS X
            case 7:
                break;

            // 8 - Windows 8
            case 8:
                break;

            // 9 - Amazon
            case 9:
                break;

            // 10 - Safari
            case 10:
                break;

            // Invalid device type value
            default:
                throw new PushwooshException('The \'deviceType\' value \'' . $this->deviceType . '\' is invalid !');
                break;
        }
    }