public function getWorkspaceAdditionalDatas(SharedWorkspace $sws)
 {
     $url = 'api/workspaces/' . $sws->getRemoteId() . '/additional/datas.json';
     $serverOutput = $this->apiManager->url($this->targetFriend, $url);
     $workspace = json_decode($serverOutput, true);
     if ($workspace === null || array_key_exists('error', $workspace)) {
         return array();
     }
     return $workspace;
 }