@Override
    public String toString() {
        return "Batch(" +
            "baseOffset=" + baseOffset +
            ", epoch=" + epoch +
            ", appendTimestamp=" + appendTimestamp +
            ", sizeInBytes=" + sizeInBytes +
            ", lastOffset=" + lastOffset +
            ", records=" + records +
            ", controlRecords=" + controlRecords +
            ')';
    }
The number of bytes used by this batch.
raft/src/main/java/org/apache/kafka/raft/Batch.java