protected function initModelManager()
    {
        $managerClass = $this->getModel();
        $modelManager = $this->newModelManagerInstance($this->getModel());
        if ($modelManager instanceof RecordManager) {
            $this->modelManager = $this->newModelManagerInstance($this->getModel());
        } else {
            throw new Exception(
                "invalid ModelManager name [$managerClass] 
                for controller [" . $this->getClassName() . "]"
            );
        }
    }