four.js

  dequeue() {
    if (this.workingOnPromise) {
      return false;
    }
    const item = this.queue.shift();
    if (!item) {
      return false;
    }
    try {
      this.workingOnPromise = true;
      item.promise()
        .then((value) => {
          this.workingOnPromise = false;
          item.resolve(value);
          this.dequeue();
        })
        .catch(err => {
          this.workingOnPromise = false;
          item.reject(err);
          this.dequeue();
        })
    } catch (err) {
      this.workingOnPromise = false;
      item.reject(err);
      this.dequeue();
    }
    return true;
  }