private String taskTransactionalId(ConnectorTaskId id) {
        return taskTransactionalId(config.groupId(), id.connector(), id.task());
    }
Using the admin principal for this connector, perform a round of zombie fencing that disables transactional producers
for the specified number of source tasks from sending any more records.
@param connName the name of the connector
@param numTasks the number of tasks to fence out
@param connProps the configuration of the connector; may not be null
@return a {@link KafkaFuture} that will complete when the producers have all been fenced out, or the attempt has failed
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/Worker.java