hljs-attr">"Body font"</span>: {
      <span class="hljs-attr">"value"</span>: [<span class="hljs-string">"Helvetica"</span>, <span class="hljs-string">"Arial"</span>],
      <span class="hljs-attr">"type"</span>: <span class="hljs-string">"font"</span>
    }
  }
  </code></pre>
  </aside>

  </section><section id="duration"><div class="header-wrapper"><h3 id="x8-4-duration"><bdi class="secno">8.4 </bdi>Duration</h3><a class="self-link" href="#duration" aria-label="Permalink for Section 8.4"></a></div>
  <p