public function getPairedDevices($refresh = false)
    {
        if ($refresh === false) {
            $device = Discovery::lookupDevice('ip', $this->ip);
            if (isset($device['device']) && is_array($device['device'])) {
                return $device['device'];
            }
        }

        $service = $this->services['BridgeService']['serviceType'];
        $controlUrl = $this->services['BridgeService']['controlURL'];
        $method = 'GetEndDevices';
        $arguments = [
            'DevUDN'      => $this->getUDN($refresh),
            'ReqListType' => 'PAIRED_LIST'
        ];

        $rs = $this->client->request($controlUrl, $service, $method, $arguments);
        $rs = $this->unwrapResponse($rs);
        $rs = WemoClient::xmlToArray($rs['u:GetEndDevicesResponse']['DeviceLists']);

        // Standalone devices.
        $devices = $rs['DeviceLists']['DeviceList']['DeviceInfos'];
        if(static::isArrayAssoc($devices)) {
            $devices = $rs['DeviceLists']['DeviceList']['DeviceInfos']['DeviceInfo'];
        }
        foreach ($devices as $k => $d) {
            $d['IsGroupAction'] = 'NO';
            $devices[$k] = $d;
        }
        // Grouped devices.
        $groupedDeviceList = [];
        $groupedDevices = $rs['DeviceLists']['DeviceList']['GroupInfos'];
        if(static::isArrayAssoc($groupedDevices)) {
            $groupedDeviceList[] = $rs['DeviceLists']['DeviceList']['GroupInfos']['GroupInfo'];
        }
        foreach ($groupedDeviceList as $gd) {
            if(!empty($gd['GroupID']) && !empty($gd['GroupName']) && !empty($gd['GroupCapabilityValues'])) {
                $devices[] = [
                    'DeviceID'      => $gd['GroupID'],
                    'FriendlyName'  => $gd['GroupName'],
                    'CurrentState'  => $gd['GroupCapabilityValues'],
                    'productName'   => $gd['DeviceInfos']['DeviceInfo'][0]['productName'],
                    'IsGroupAction' => 'YES'
                ];
                if(isset($gd['DeviceInfos']) && isset($gd['DeviceInfos']['DeviceInfo'])){
                    foreach($gd['DeviceInfos']['DeviceInfo'] as $gdi){
                        $gdi['IsGroupAction'] = 'NO';
                        $devices[] = $gdi;
                    }
                }
            }
        }
        return $devices;
    }