title: Customizing the batch with specific elements
body: <p>I am a fresh starter with PyTorch. Strangely I cannot find anything related to this, although it seems rather simple.</p>
  <p>I want to structure my batch with specific examples, like all examples per batch having the same label, or just fill the batch with examples of just 2 classes.</p>
  <p>How would I do that? For me, it seems the right place within the data loader and not in the dataset? As the data loader is responsible for the batches and not the dataset?</p>
  <p>Is there a simple minimal example?</p>