def test_lpips_computes_grad(x, y, device: str) -> None:
x.requires_grad_()
loss_value = LPIPS()(x.to(device), y.to(device))
loss_value.backward()
assert x.grad is not None, NONE_GRAD_ERR_MSG
def test_lpips_computes_grad(prediction: torch.Tensor, target: torch.Tensor,
device: str) -> None:
prediction.requires_grad_()
loss_value = LPIPS()(prediction.to(device), target.to(device))
loss_value.backward()
assert prediction.grad is not None, NONE_GRAD_ERR_MSG