Method cancel

lib/internal/webstreams/readablestream.js:347–355

* @param {any} [reason] * @returns { Promise }

(reason = undefined)

   * @returns { Promise<void> }
   */
  cancel(reason = undefined) {
    if (!isReadableStream(this))
      return PromiseReject(new ERR_INVALID_THIS('ReadableStream'));
    if (isReadableStreamLocked(this)) {
      return PromiseReject(
        new ERR_INVALID_STATE.TypeError('ReadableStream is locked'));
    }
    return readableStreamCancel(this, reason);
  }

  /**
   * @param {{