anchor.diff:    };
   
     // - - - - - - - - - - - - - - - - - - - - - - - -
  -  const setCheckoutButtonTip = () => {
  -    // Prefer 'checkout' to 'revert' since in a group exercises
  -    // you can revert to other avatar's traffic-lights.
  -    const $button = $('#checkout-button');
  -    const tip = `make this traffic-light's<br/>files your current files`;
  -    cd.createTip($button, tip);
  -  };
  -
  -  // - - - - - - - - - - - - - - - - - - - - - - - -
     review.setupButton = (name, handler) => {
       const button = `<button id="${name}-button" type="button"></button>`;
       $(`#${name}-button-box`).html(button);
  
positive.code:   // - - - - - - - - - - - - - - - - - - - - - - - -
    cd.setReviewData = (version, id, groupId, avatarIndex, wasIndex, nowIndex) => {
      // Called only from app/views/kata/_traffic_lights.html.erb
      // The [resume] & [checkout] buttons are only shown on kata/edit. [1]
      review.params = {
            version:version,
                 id:id,
  
negative.code:          wasIndex:wasIndex,
           nowIndex:nowIndex
      };
      review.fadeIntoReviewPage();
      review.refresh();
    };
  
    // - - - - - - - - - - - - - - - - - - - - - - - -
    review.fadeIntoReviewPage = () => {
      $kataPage.fadeOut('fast', () => {
        review.page.fadeIn('fast');
      });
  