yl</span><span class="op">)</span><span class="op">)</span><span class="op">)</span> <span class="op">+</span></span></span>
<span class="r-in"><span>    <span class="co"># only show manual transmission cars</span></span></span>
<span class="r-in"><span>    <span class="co"># in the second interactive layer</span></span></span>
<span class="r-in"><span>    <span class="fu">active</span><span class="op">(</span>active <span class="op">=</span> <span class="va">mtcars</span><span class="op">$</span><span clas