public function newDoc($profile, $initDoc = null)
    {
        $doc = new CollectionDocJson(null, $this->_auth);
        if ($initDoc) {
            $doc->setDocument($initDoc);
        }

        // get the profile link
        $urn = self::FETCH_PROFILE;
        $link = $this->home->link($urn);
        if (empty($link)) {
            throw new LinkException("Unable to find link $urn in home doc");
        }
        $href = $link->expand(['guid' => $profile]);

        // set the link
        $doc->links->profile = [new \StdClass()];
        $doc->links->profile[0]->href = $href;
        return $doc;
    }