presto-spi/src/main/java/io/prestosql/spi/block/RowBlock.java/RowBlock/getRetainedSizeInBytes
class RowBlock:    @Override
    public long getRetainedSizeInBytes()
    {
        long retainedSizeInBytes = this.retainedSizeInBytes;
        for (Block fieldBlock : fieldBlocks) {
            retainedSizeInBytes += fieldBlock.getRetainedSizeInBytes();
        }
        return retainedSizeInBytes;
    }