public void Handle()
{
vm.EnsureSlots(2);
vm.SetSlotNull(0, 1);
Assert.AreEqual(WrenType.Null, vm.GetSlotType(0));
vm.SetSlotDouble(0, 9);
var handle = vm.GetSlotHandle(0);
vm.SetSlotHandle(1, handle);
Assert.AreEqual(9, vm.GetSlotDouble(1));
handle.Release();
}