anchor.diff:  
       const diffContent = $('#diff-content');
       const diffFilenames = $('#diff-filenames');
  -    diffFilenames.html(makeDiffFilenames(param.diffs));
  +    diffFilenames.html(makeDiffFilenames(review.params.diffs));
       resetFilenameAddedDeletedLineCountHandlers();
  -    diffContent.html(makeDiffContent(param.diffs));
  -    buildDiffFilenameHandlers(param.diffs);
  -    showFile(param.currentFilenameId);
  +    diffContent.html(makeDiffContent(review.params.diffs));
  +    buildDiffFilenameHandlers(review.params.diffs);
  +    showFile(review.params.currentFilenameId);
     };
   
     const showFile = (filenameId) => {
  
positive.code:   const makeTrafficLightsHtml = () => {
      let html = '';
      let number = 1;
      param.events.forEach(event => {
        if (isVisible(event)) {
          html += makeTrafficLightHtml(event, number);
          number += 1;
  
negative.code:       diff.section_index += 1;
        diff.section_index %= diff.section_count;
      }
      review.params.filename = filename;
      diff.clicked = true;
    };
  
  