Method open

Libraries/Network/XMLHttpRequest.js:433–449

(method: string, url: string, async: ?boolean)

  }

  open(method: string, url: string, async: ?boolean): void {
    /* Other optional arguments are not supported yet */
    if (this.readyState !== this.UNSENT) {
      throw new Error('Cannot open, already sending');
    }
    if (async !== undefined && !async) {
      // async is default
      throw new Error('Synchronous http requests are not supported');
    }
    if (!url) {
      throw new Error('Cannot load an empty url');
    }
    this._method = method.toUpperCase();
    this._url = url;
    this._aborted = false;
    this.setReadyState(this.OPENED);
  }

  send(data: any): void {
    if (this.readyState !== this.OPENED) {