presto-spi/src/main/java/io/prestosql/spi/block/AbstractSingleRowBlock.java/AbstractSingleRowBlock/writePositionTo
class AbstractSingleRowBlock:    @Override
    public void writePositionTo(int position, BlockBuilder blockBuilder)
    {
        checkFieldIndex(position);
        getRawFieldBlock(position).writePositionTo(rowIndex, blockBuilder);
    }