public function modelType($modelType = null)
    {
        deprecationWarning(
            get_called_class() . '::modelType() is deprecated. ' .
            'Use setModelType()/getModelType() instead.'
        );
        if ($modelType === null) {
            return $this->_modelType;
        }

        $this->_modelType = $modelType;

        return $this;
    }