anchor.diff:  
     // - - - - - - - - - - - - - - - - - - - - - - - -
   
  -  var refresh = function() {
  +  const refresh = () => {
       if (inDialog()) {
         reviewRefresh();
       } else {
  
positive.code:   // refresh [fork] {create a new practice-session}
    //-----------------------------------------
  
    var refreshForkButton = function() {
      var button = $('#fork-button');
      cd.setTip(button, function() {
        var tip = 'setup a new session from ' + param.avatar + ' ' + param.nowTag;
        cd.showHoverTip(button, tip);
      });
    };
  
    // - - - - - - - - - - - - - - - - - - - - - - - -
  
    var doFork = function() {
  
      var fork_params = {
            id: param.id,
        avatar: param.avatar,
           tag: param.nowTag
      };
      $.getJSON('/forker/fork', fork_params, function(data) {
        if (data.forked) {
          cd.newDojoDialog(data);
        } else {
  
negative.code: 
    // - - - - - - - - - - - - - - - - - - - - - - - -
  
    const showLatestNoDiff = () => {
      const lastTag = -1;
      param.wasTag = lastTag;
      param.nowTag = lastTag;
      refresh();
  