alidation</legend>
        <form class="was-validated">
          <div class="form-group is-invalid">
            <div class="custom-switch pl-0">
              <input class="custom-switch-input" id="example_13" type="checkbox">
              <label class="custom-switch-btn" for="example_13"></label>
            </div>
          </div>
        </form>
        <p class="my-2">I'm <code>invalid</code></p>

      </div>
    </div>
  </div>
</body>
</html>
