presto-blackhole/src/main/java/io/prestosql/plugin/blackhole/BlackHolePageSource.java/BlackHolePageSource/BlackHolePageSource
class BlackHolePageSource:    BlackHolePageSource(Page page, int count, ListeningScheduledExecutorService executorService, Duration pageProcessingDelay)
    {
        this.page = requireNonNull(page, "page is null");
        checkArgument(count >= 0, "count is negative");
        this.pagesLeft = count;
        this.executorService = requireNonNull(executorService, "executorService is null");
        this.pageProcessingDelayInMillis = requireNonNull(pageProcessingDelay, "pageProcessingDelay is null").toMillis();
        this.memoryUsageBytes = page.getSizeInBytes();
    }