public boolean transactionalLeaderEnabled() {
        return exactlyOnceSourceSupport.usesTransactionalLeader;
    }
@return whether the Connect cluster's leader should use a transactional producer to perform writes to the config
topic, which is useful for ensuring that zombie leaders are fenced out and unable to write to the topic after a
new leader has been elected.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/DistributedConfig.java