public function sendGetProfilePicture($number, $large = false)
    {
        $msgId = $this->nodeId['getprofilepic'] = $this->createIqId();

        $hash = [];
        $hash['type'] = 'image';
        if (!$large) {
            $hash['type'] = 'preview';
        }
        $picture = new ProtocolNode('picture', $hash, null, null);

        $node = new ProtocolNode('iq',
            [
                'id'    => $msgId,
                'type'  => 'get',
                'xmlns' => 'w:profile:picture',
                'to'    => $this->getJID($number),
            ], [$picture], null);

        $this->sendNode($node);
    }