(instance);
    instance.mark("lorem", {
      debug: true,
      done: function(counter) {
        const end = new Date(),
          time = end.getTime() - start.getTime();
        console.log(
          "Time elapsed: " + time + "ms.",
          "Elements: " + counter
        );
        setTimeout(function() {
          start = new Date();
          instance.unmark({
            debug: true,
            done: function() {
              const end = new Date(),
                time = end.getTime() - start.g