presto-spi/src/main/java/io/prestosql/spi/block/AbstractRowBlock.java/AbstractRowBlock/getEstimatedDataSizeForStats
class AbstractRowBlock:    @Override
    public long getEstimatedDataSizeForStats(int position)
    {
        checkReadablePosition(position);

        if (isNull(position)) {
            return 0;
        }

        Block[] rawFieldBlocks = getRawFieldBlocks();
        long size = 0;
        for (int i = 0; i < numFields; i++) {
            size += rawFieldBlocks[i].getEstimatedDataSizeForStats(getFieldBlockOffset(position));
        }
        return size;
    }