@Override
  public boolean executeFromValidate(ConfigNodeProcedureEnv env) throws SubscriptionException {
    LOGGER.info("AlterTopicProcedure: executeFromValidate");

    subscriptionInfo.get().validateBeforeAlteringTopic(updatedTopicMeta);

    existedTopicMeta = subscriptionInfo.get().getTopicMeta(updatedTopicMeta.getTopicName());

    return true;
  }
This should be called after {@link #executeFromValidate}.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/impl/subscription/topic/AlterTopicProcedure.java