public StoredChannel setTopicId(String topicId) {
    lock.lock();
    try {
      this.topicId = topicId;
    } finally {
      lock.unlock();
    }
    return this;
  }
public StoredChannel setTopicId ( String topicId ) { lock . lock ( ) ; try { this . topicId = topicId ; } finally { lock . unlock ( ) ; } return this ; }
Sets the opaque ID for the subscribed resource that is stable across API versions or
{@code null} for none.