r</span> <span class="n">clazz</span><span class="p">,</span> <span class="n">n_sample</span> <span class="ow">in</span> <span class="n">class_counts</span><span class="o">.</span><span class="n">items</span><span class="p">():</span>
        <span class="k">if</span> <span class="n">n_sample</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
            <span class="n">errs</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="sa">f<