title: Passing tensorDataset or Dataloader to skorch
body: <p>I want to apply cross validation in Pytorch using skorch, so I prepared my model and my tensorDataset which returns (image,caption and captions_length) and so it has X and Y, so I'll not be able to set Y in the method </p>
  
  <pre><code>net.fit(dataset)
  </code></pre>
  
  <p>but when I tried that I got an error :</p>
  
  <blockquote>
    <p>ValueError: Stratified CV requires explicitly passing a suitable y</p>
  </blockquote>
  
  <p>Here's part of my code:</p>
  
  <pre><code>start = time.time()
  net = NeuralNetClassifier(
          decoder, criterion= nn.CrossEntropyLoss,
          max_epochs=args.epochs,
          lr=args.lr,
          optimizer=optim.SGD,
          device='cuda',  # uncomment this to train with CUDA
         )
  net.fit(dataset, y=None)
  end = time.time()
  </code></pre>