use <a href="/collab.html#CollabDataBunch.from_df"><code>CollabDataBunch.from_df</code></a> than a pytorch <a href="https://pytorch.org/docs/stable/data.html#torch.utils.data.Dataset"><code>Dataset</code></a>) and represents the unique tags that appear in your data.</li>
<li>maybe a <code>loss_func</code> attribute: that is going to be used by <a href="/basic_train.html#Learner"><code>Learner</code></a> as a default loss function, so if you know your custom <a href="https://pytorch.org/docs/stable/data.html