presto-main/src/main/java/io/prestosql/operator/HashSemiJoinOperator.java/HashSemiJoinOperator/HashSemiJoinOperator
class HashSemiJoinOperator:    public HashSemiJoinOperator(
            Optional<WorkProcessor<Page>> sourcePages,
            SetSupplier channelSetFuture,
            int probeJoinChannel,
            Optional<Integer> probeHashChannel,
            MemoryTrackingContext memoryTrackingContext)
    {
        pages = sourcePages.orElse(pageBuffer.pages())
                .transform(new SemiJoinPages(
                        channelSetFuture,
                        probeJoinChannel,
                        probeHashChannel,
                        requireNonNull(memoryTrackingContext, "memoryTrackingContext is null").aggregateUserMemoryContext()));
    }