From a Dataloader, actually. It should be correct:
    testset = torchvision.datasets.CIFAR10(root='./data', train=False, download=True, transform=transform_test)
    testloader = torch.utils.data.DataLoader(testset, batch_size=100, shuffle=False, num_workers=2)
    ...
    for batch_idx, (data, target) in enumerate(trainloader):
    ...