Oh, I see! When I tranform to 1.0 preview.It really works.Thank you a lot.I’m a freshman to PyTorch not a long time.I found that PyTorch 0.4.1 is the lastest stable version.As far as I know, people prefer to choose the stable one to develop or do research.But as above, some tutorial codes are written in preview 1.0.So which one should I choose to learn PyTorch, stable 0.4.1 or  cool preview 1.0.Can you give me some advice?Thank you!