   <li>
            <p>
              <button class="cache-first">
                Cache First Request (Try it Several Times)
              </button>
            </p>
          </li>
          <li>
            <p><button class="network-only">Network Only Request</button></p>
          </li>
          <li>
            <p>
              <button class="network-first-valid">
                Network First Request (Valid URL)
              </button>
            </p>
          </li>
          <li>
            <p>
