code: function noNew() {
        return finish(function(err) {
          if (err) return next(err);
  
          // If there was a body initially, respond that there's been no change
          if (ourEtag) return res.send(304);
  
          // Otherwise, respond that there's no content (yet)
          else return res.send(204);
        });
      }
docs: Callback for if there's no new body by the time we're supposed to respond.