title: accordion toggle icon not visible
body: <p><strong>Accordion toggle icon not visible, just blank square is present</strong>
  <a href="https://i.stack.imgur.com/3Im9Q.png" rel="nofollow noreferrer">In image I am getting blank square brackets</a>
  <div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.accordion-toggle:after {
          color: #aaa;
          content: "\f146";
          display: block;
          font-family: FontAwesome;
          font-size: 10px;
          line-height: 36px;
          position: absolute;
          top: 3px;
          right: 15px;
          }
          
      .accordion-toggle.collapsed:after {
          content: "\f0fe";
      }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="CLUSPanel" class="panel"&gt;
   &lt;div class="panel-heading"&gt;
     &lt;a class="accordion-toggle collapsed" 
              data-toggle="collapse" data-parent="#accordion" href="#CLUSPanelBody"&gt;
              
            some text
  
        &lt;/a&gt;
     &lt;/div&gt;  
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>