anchor.diff:  
     //- - - - - - - - - - - - - - - - - - - - - - -
     // Revert checkbox
  -  // Note: if you turn predict off then on, the revert-container
  -  // gets slightly taller!! Perhaps it would be better to leave
  -  // the revert-container visible. If clicked it would auto-set
  -  // predict.
   
     const $revertContainer = $('#revert-checkbox-container');
     const $revert  = $('#revert-checkbox');
  
positive.code: 
    const revertCheckBoxChanged = () => {
      if ($revert.prop('checked')) {
        cd.settings.revert('on');
      } else {
        cd.settings.revert('off');
      }
      cd.kata.editor.refocus();
    };
  
    //- - - - - - - - - - - - - - - - - - - - - - -
  
negative.code:   };
  
    const predictOff = () => {
      cd.settings.predict('off');
      if ($revert.is(':checked')) {
        // predict just went to !checked,
        // so ensure revert is !checked
        $revert.prop('checked', false);
        revertOff();
      }
      $buttonsContainer.slideUp('slow', () => {
        cd.kata.testButton.show();
        cd.kata.predictCounts.hide();
  