li><a href="#return-guarantee-required" id="toc-return-guarantee-required" class="nav-link" data-scroll-target="#return-guarantee-required">Return guarantee required</a></li>
  </ul></li>
  <li><a href="#void-functions-as-statements" id="toc-void-functions-as-statements" class="nav-link" data-scroll-target="#void-functions-as-statements">Void Functions as Statements</a>
  <ul class="collapse">
  <li><a href="#void-functions" id="toc-void-functions" class="nav-link" data-scroll-target="#void-functions">Void 