public function rowsPerPage($modelName)
    {
        $dataTable = app('admin_datatable');

        //get the inputted rows and the model rows
        $rows = (int) $this->request->input('rows', 20);
        $dataTable->setRowsPerPage(app('session.store'), 0, $rows);

        return response()->JSON(array('success' => true));
    }