function ValidateController ({ accountId, controllerId, defaultController, onError }: Props): React.ReactElement<Props> | null {
  const { t } = useTranslation();
  const { api } = useApi();
  const bondedId = useCall<string | null>(controllerId ? api.query.staking.bonded : null, [controllerId], OPT_BOND);
  const stashId = useCall<string | null>(controllerId ? api.query.staking.ledger : null, [controllerId], OPT_STASH);