anchor.diff:  <div class="tab-filenames">
     <div class="tab filename">cyber-dojo.sh</div>
     <div class="tab REPL">+REPL</div>
  +  <%# These three float:right so are in reverse order of appearance %>  
  +  <div class="tab status">status</div>
     <div class="tab stderr">stderr</div>
     <div class="tab stdout">stdout</div>
   </div>
  
positive.code:   setupFileTabClickHandler(tabs.filename());
    setupFileTabClickHandler(tabs.stdout());
    setupFileTabClickHandler(tabs.stderr());
    setupReplTabClickHandler(tabs.repl());
  
  });
  
negative.code:     const tabNames = [];
      tabNames.push(tabs.stdout().text());
      tabNames.push(tabs.stderr().text());
      tabNames.push(tabs.status().text());
      tabNames.push('status');
      tabNames.push(tabs.repl().text());
      return tabNames.includes(filename);
  