f_test_null_function(typval_T *argvars UNUSED, typval_T *rettv)
{
    rettv->v_type = VAR_FUNC;
    rettv->vval.v_string = NULL;
}
f_test_null_function(typval_T *argvars UNUSED, typval_T *rettv)
{
    rettv->v_type = VAR_FUNC;
    rettv->vval.v_string = NULL;
}