title: How to find functions imported from torch._C in source code
body: <p>I'm trying to track down the implementation of <code>torch.nn.NLLLoss</code> in the source code. I got as far as a call to <code>torch._C.nll_loss</code> in the function <code>nll_loss</code> in the file <code>torch.nn.functional</code>. But I can't find a place where _C is created.</p>
  
  <p>Anyone have any info on this?  </p>