public void addPartitionToFetch(TopicIdPartition topicIdPartition, Acknowledgements partitionAcknowledgements) {
        nextPartitions.put(topicIdPartition.topicPartition(), topicIdPartition);
        if (partitionAcknowledgements != null) {
            nextAcknowledgements.put(topicIdPartition, partitionAcknowledgements);
        }
    }
All the partitions in the share session.
clients/src/main/java/org/apache/kafka/clients/consumer/internals/ShareSessionHandler.java