PyObject *result_ref;

switch ( flag ) {
    case 1:
    result_ref = new_reference_to( get_result_1().ptr() );
    break;

    case 2:
    result_ref = new_reference_to( get_result_2().ptr() );
    break;

    default:
    result_ref = nullptr;
}

return result_ref;    // Still return nullptr if flag is invalid