@Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        ProducerIdsBlock that = (ProducerIdsBlock) o;
        return assignedBrokerId == that.assignedBrokerId && firstProducerId == that.firstProducerId && blockSize == that.blockSize;
    }
Get the first ID of the next block following this one.
server-common/src/main/java/org/apache/kafka/server/common/ProducerIdsBlock.java