public function clear()
{
$this->sessionCheck();
if (Zotero_Sync::userIsReadLocked($this->userID) || Zotero_Sync::userIsWriteLocked($this->userID)) {
$message = "You cannot reset server data while one of your libraries " . "is locked for syncing. Please wait for all related syncs to complete.";
$this->error(400, 'SYNC_LOCKED', $message);
}
StatsD::increment("sync.clear");
Zotero_Users::clearAllData($this->userID);
$this->responseXML->addChild('cleared');
$this->end();
}