constructor() {
    /**
     * @export {!Array<string>}
     */
    this.owners;

    /**
     * @export {!Array<string>}
     */
    this.writers;

    /**
     * @export {!Array<string>}
     */
    this.readers;

    /**
     * Owners, writer, and reader email addresses that are known to be groups.
     * @export {!Set<string>|undefined}
     */
    this.groups;

    /**
     * @export {undefined|boolean}
     */
    this.all_users_can_read;
  }
An access control list for an asset. The strings are all email addresses (for
either individuals or groups).
@record @struct