Notice that in PyTorch version, a tensor and index operation could be written like below

```
tensor_test = torch.randn(1, 27)
tensor_test[:, 5:]
```

In C++ libtorch version, i noticed that i have to set the `dim=-1`

in slice function so that i could get the right answer. But i don’t understand what `dim=-1`

means.

```
tensor_test = torch::randn({1, 27})
tensor_test.slice(-1, 5, tensor_test.sizes()[1])
```