text: const { performance } = require('perf_hooks');
  
  class Timer {
    constructor() {
      this.startTime = performance.now();
      this.endTime = null;
      this.elapsedMilli = null;
    }
  
    end () {
      this.endTime = performance.now();
      this.elapsedMilli = this.endTime - this.startTime;
    }
  }
  
  module.exports = Timer;
  