presto-spi/src/main/java/io/prestosql/spi/block/LazyBlock.java/LazyBlock/getPositionsSizeInBytes
class LazyBlock:    @Override
    public long getPositionsSizeInBytes(boolean[] positions)
    {
        if (!isLoaded()) {
            return 0;
        }
        return getBlock().getPositionsSizeInBytes(positions);
    }