private function doGroup($method, $args)
    {
        $meta = $this->internal->getMetaVals(
            $args,
            array('channel' => $this->cfg['channel'])
        );
        $this->rootInstance->groupStackRef[] = array(
            'channel' => $meta['channel'],
            'collect' => $this->cfg['collect'],
        );
        if (!$this->cfg['collect']) {
            return;
        }
        if (empty($args)) {
            // give a default label
            $caller = $this->utilities->getCallerInfo();
            if (isset($caller['class'])) {
                $args[] = $caller['class'].$caller['type'].$caller['function'];
                $meta['isMethodName'] = true;
            } elseif (isset($caller['function'])) {
                $args[] = $caller['function'];
            } else {
                $args[] = 'group';
            }
        }
        $this->appendLog($method, $args, $meta);
    }