PicklerMemoProxy_traverse(PicklerMemoProxyObject *self,
                          visitproc visit, void *arg)
{
    Py_VISIT(self->pickler);
    return 0;
}
PicklerMemoProxy_traverse(PicklerMemoProxyObject *self,
                          visitproc visit, void *arg)
{
    Py_VISIT(self->pickler);
    return 0;
}