A strange warning 'Unresolved attribute reference 'to' for class 'int' '

I am learning how to build a LeNet5 CNN using pytorch. There is warning says 'Unresolved attribute reference ‘to’ for class ‘int’ ’ I dont know how to deal with it. Here is the code with warning at images = images.to(device)

for epoch in range(num_epochs):
    for i, (images, labels) in enumerate(train_loader):
        images = images.to(device)  
        labels = labels.to(device)

        outputs = model(images) 
        loss = cost(outputs, labels)  

        optimizer.zero_grad()  
        loss.backward()  
        optimizer.step()  

        if (i + 1) % 400 == 0:
            print('Epoch [{}/{}], Step [{}/{}], Loss: {:.4f}'
                  .format(epoch + 1, num_epochs, i + 1, total_step, loss.item()))

/(ㄒoㄒ)/~~ plz help me.

maybe type(labels) == int or type(images) == int