constructor(code, opt_message, opt_credential) {
    super();
    /** @export */
    this.code = AuthUIError.ERROR_CODE_PREFIX + code;
    /** @export */
    this.message = opt_message ||
        AuthUIError.getDefaultErrorMessage_(this.code) || '';
    /** @export */
    this.credential = opt_credential || null;
  }
@param {!AuthUIError.Error} code The short error code.
@param {?string=} opt_message The human-readable message.
@param {?firebase.auth.AuthCredential=} opt_credential The Auth credential
    that failed to link to the anonymous user.