Hi, Im trying to understand the code of WGAN-gp 95.
... create_graph=True, retain_graph=True,...
However, I did not understand what the argument create_graph is doing?
I’ve checked the doc 51 however it’s not clear for me. Where did it calculate the second-order gradient?

If  True , graph of the derivative will be constructed, allowing to compute higher order derivative products. Default:  False .

When I change it to
... create_graph=True, retain_graph=True,...
or
... create_graph=True, retain_graph=None,...
the code still works, but the model generates same image (model collapse?)