WhichBrowser\Analyser\Derive::deriveDeviceSubType PHP Method

    private function &deriveDeviceSubType()
    {
        if ($this->data->device->type == 'mobile' && empty($this->data->device->subtype)) {
            $this->data->device->subtype = 'feature';
            if (in_array($this->data->os->getName(), ['Android', 'Bada', 'BlackBerry', 'BlackBerry OS', 'Firefox OS', 'iOS', 'iPhone OS', 'Kin OS', 'Maemo', 'MeeGo', 'Palm OS', 'Sailfish', 'Series60', 'Series80', 'Tizen', 'Ubuntu Touch', 'Windows Mobile', 'Windows Phone', 'webOS'])) {
                $this->data->device->subtype = 'smart';
            }
            if (isset($this->data->os->name) && in_array($this->data->os->name, ['Windows Phone'])) {
                $this->data->device->subtype = 'smart';
            }
            if (isset($this->data->os->family) && in_array($this->data->os->family->getName(), ['Android'])) {
                $this->data->device->subtype = 'smart';
            }
        }
        return $this;
    }