presto-spi/src/main/java/io/prestosql/spi/block/SingleRowBlockWriter.java/SingleRowBlockWriter/retainedBytesForEachPart
class SingleRowBlockWriter:    @Override
    public void retainedBytesForEachPart(BiConsumer<Object, Long> consumer)
    {
        for (BlockBuilder fieldBlockBuilder : fieldBlockBuilders) {
            consumer.accept(fieldBlockBuilder, fieldBlockBuilder.getRetainedSizeInBytes());
        }
        consumer.accept(this, (long) INSTANCE_SIZE);
    }