Method drainText_

third_party/subscriptions-project/swg.js:13646–13650

* Drains the response and returns the text. * @return {!Promise } * @private

()

   * @private
   */
  drainText_() {
    assert(!this.bodyUsed, 'Body already used');
    this.bodyUsed = true;
    return Promise.resolve(this.xhr_.responseText);
  }

  /**
   * Drains the response and returns a promise that resolves with the response