title: add/remove css class on the weightage
body: <p>I have a <code>div</code> container with <code>8 child div elements</code> which indicate a some color bars. Each div block contains a <code>weight-age</code> of <code>12.5%</code>. </p>
  
  <pre><code>&lt;div class="progress-stacked" id="progress-div"&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%; margin-right: 11px;"&gt;&lt;/div&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%; margin-right: 11px;"&gt;&lt;/div&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%; margin-right: 11px;"&gt;&lt;/div&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%; margin-right: 11px;"&gt;&lt;/div&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%; margin-right: 12px;"&gt;&lt;/div&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%; margin-right: 12px;"&gt;&lt;/div&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%; margin-right: 12px;"&gt;&lt;/div&gt;
      &lt;div class="progress-bar progress-bar-fail" style="width: 10%;"&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>How would i replace the class <code>progress-bar-fail</code> with <code>progress-bar-success</code> for the value i get from API. For instance if i get 12.5, i want the first child to have <code>progress-bar-success</code> instead of <code>progress-bar-fail</code>. </p>
  
  <p>If its <code>25</code>, then two child div should be replaced with <code>progress-bar-success</code> instead of <code>progrss-bar-fail</code>.</p>