code: function timer(digits)
  {
      var t0 = new Date().getTime();
  
      return function () {
          var t1 = new Date().getTime();
          // linter doesn't like new Number(...)
          return Number.prototype.toFixed.call((t1 - t0) / 1000, digits || 3);
      };
  }
docs: Returns a closure that, when called, returns the number of seconds
  since the timer() function was itself called.