"n">context</span><span class="p">:</span>
            <span class="k">if</span> <span class="ow">not</span> <span class="n">mask</span><span class="p">[</span><span class="n">j</span><span class="p">]:</span>
                <span class="n">post_idxs</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">j</span><span class="p">)</span>
            <span class="n">j</span> <span class="o">+=</span> <span class="mi">1</span>
        <span class="k">for</span> <spa