requires_grad=True for an input datapoint?

[ggbioing]

tutorials/advanced_source/super_resolution_with_onnxruntime.py

Line 144 in f4ebb4d

x = torch.randn(batch_size, 1, 224, 224, requires_grad=True)

It is obscure to me why there is the need to set the flag requires_grad to True for datapoint "x", which has no parameters to be learnt.
Is it something required to export the model in onnx?

Thanks.

cc @titaiwangms @xadupre @justinchuby @BowenBao

[svekars]

cc: @thiagocrepaldi

[svekars]

For a faster answer, please post in https://discuss.pytorch.org/

[justinchuby]

Thanks, we should redo this tutorial.