presto-main/src/main/java/io/prestosql/operator/PageUtils.java/PageUtils/recordMaterializedBytes
class PageUtils:    public static void recordMaterializedBytes(Page page, LongConsumer sizeInBytesConsumer)
    {
        // account processed bytes from lazy blocks only when they are loaded
        long loadedBlocksSizeInBytes = 0;

        for (int i = 0; i < page.getChannelCount(); ++i) {
            Block block = page.getBlock(i);
            long initialSize = block.getSizeInBytes();
            loadedBlocksSizeInBytes += initialSize;
            listenForLoads(block, new BlockSizeListener(block, sizeInBytesConsumer, initialSize));
        }

        if (loadedBlocksSizeInBytes > 0) {
            sizeInBytesConsumer.accept(loadedBlocksSizeInBytes);
        }
    }