presto-main/src/main/java/io/prestosql/operator/unnest/UnnestOperator.java/UnnestOperator/resetBlockBuilders
class UnnestOperator:    private void resetBlockBuilders()
    {
        for (int i = 0; i < replicateTypes.size(); i++) {
            Block newInputBlock = currentPage.getBlock(replicateChannels.get(i));
            replicatedBlockBuilders.get(i).resetInputBlock(newInputBlock);
        }

        for (int i = 0; i < unnestTypes.size(); i++) {
            int inputChannel = unnestChannels.get(i);
            Block unnestChannelInputBlock = currentPage.getBlock(inputChannel);
            unnesters.get(i).resetInput(unnestChannelInputBlock);
        }
    }