Method execute

lib/index.js:2504–2515

()

  }

  execute() {
    var fun;
    if (this.failed) {
      while ((fun = this.queue.shift())) {
        fun(this.failed);
      }
    } else {
      while ((fun = this.queue.shift())) {
        fun();
      }
    }
  }

  fail(err) {
    this.failed = err;