 class="n">data_dir</span><span class="p">)</span> <span class="o">/</span> <span class="s1">&#39;train_tiles&#39;</span><span class="p">)</span>
    <span class="n">val_ds</span> <span class="o">=</span> <span class="n">XeniumDataset</span><span class="p">(</span><span class="n">root</span><span class="o">=</span><span class="n">Path</span><span class="p">(</span><span class="n">args</span><span class="o">.</span><span class="n">data_dir</span><span class="p">)</span> <span class="o">/</span> <span class="