text: /**
   * @param {string} homepage
   */
  const BrowserHistory = function (homepage) {
    this.current = {
      url: homepage,
      next: null,
      back: null
    }
  }
  
  /**
   * @param {string} url
   * @return {void}
   */
  BrowserHistory.prototype.visit = function (url) {
    this.current.next = {
      url,
      next: null,
      back: this.current
    }
    this.current = this.current.next
  }
  
  /**
   * @param {number} steps
   * @return {string}
   */
  BrowserHistory.prototype.back = function (steps) {
    while (steps !== 0 && this.current.back) {
      this.current = this.current.back
      steps--
    }
    return this.current.url
  }
  
  /**
   * @param {number} steps
   * @return {string}
   */
  BrowserHistory.prototype.forward = function (steps) {
    while (steps !== 0 && this.current.next) {
      this.current = this.current.next
      steps--
    }
    return this.current.url
  }
  
  /**
   * Your BrowserHistory object will be instantiated and called as such:
   * var obj = new BrowserHistory(homepage)
   * obj.visit(url)
   * var param_2 = obj.back(steps)
   * var param_3 = obj.forward(steps)
   */
  