<h2>Favorite books</h2>
<ul class="accordion-menu">
  <li>
    <div class="dropdownlink"><i class="fa fa-road" aria-hidden="true"></i> History
      <i class="fa fa-chevron-down" aria-hidden="true"></i>
    </div>
    <ul class="submenuItems">
      <li><a href="#">History book 1</a></li>
      <li><a href="#">History book 2</a></li>
      <li><a href="#">History book 3</a></li>
    </ul>
  </li>
  <li>
    <div class="dropdownlink"><i class="fa fa-paper-plane" aria-hidden="true"></i> Fiction
      <i class="fa fa-chevron-down" aria-hidden="true"></i>
    </div>
    <ul class="submenuItems">
      <li><a href="#">Fiction book 1</a></li>
      <li><a href="#">Fiction book 2</a></li>
      <li><a href="#">Fiction book 3</a></li>
    </ul>
  </li>
  <li>
    <div class="dropdownlink"><i class="fa fa-quote-left" aria-hidden="true"></i> Fantasy
      <i class="fa fa-chevron-down" aria-hidden="true"></i>
    </div>
    <ul class="submenuItems">
      <li><a href="#">Fantasy book 1</a></li>
      <li><a href="#">Fantasy book 2</a></li>
      <li><a href="#">Fantasy book 3</a></li>
    </ul>
  </li>
  <li>
    <div class="dropdownlink"><i class="fa fa-motorcycle" aria-hidden="true"></i> Action
      <i class="fa fa-chevron-down" aria-hidden="true"></i>
    </div>
    <ul class="submenuItems">
      <li><a href="#">Action book 1</a></li>
      <li><a href="#">Action book 2</a></li>
      <li><a href="#">Action book 3</a></li>
    </ul>
  </li>
</ul>

* {
  margin: 0;
  padding: 0;
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}

ul {
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a {
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h2 {
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}
.accordion-menu li.open .dropdownlink {
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.accordion-menu li:last-child .dropdownlink {
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.dropdownlink {
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.submenuItems a {
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  transition: all 0.4s ease-out;
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$(function() {
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    this.el = el || {};
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    this.multiple = multiple || false;
    
    var dropdownlink = this.el.find('.dropdownlink');
    dropdownlink.on('click',
                    { el: this.el, multiple: this.multiple },
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  Accordion.prototype.dropdown = function(e) {
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        //this is the ul.submenuItems
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})