lazyCreate = function() {
      'use strict';
      // Lazily render the UI.
      var ui = new goog.tweak.TweakUi(
          /** @type {!goog.tweak.Registry} */ (registry), dh);
      ui.render();
      // Put the hide link on the same line as the "Show Descriptions" link.
      // Set the style lazily because we can.
      hideLink.style.marginRight = '10px';
      var tweakElem = ui.getRootElement();
      tweakElem.insertBefore(hideLink, tweakElem.firstChild);
      ret.appendChild(tweakElem);
      return tweakElem;
    }
Creates a TweakUi inside of a show/hide link.
@param {goog.dom.DomHelper=} opt_domHelper The DomHelper to render with.
@return {!Element|undefined} The root UI element or undefined if tweaks are
    not enabled.