teps:</h5>
                <ul>
                  <br />
                  <li>
                    First of all, understand how to build a
                    <a href="barplot_basic.html">basic barplot.</a>
                  </li>
                  <br />
                  <li>
                    Second, understand how the
                    <a href="barplot_button_data_simple.html">basic version</a>
                    of the dataset transition works.
                  </li>
                  <br />
   