presto-main/src/main/java/io/prestosql/operator/HashSemiJoinOperator.java/HashSemiJoinOperator/SemiJoinPages
class HashSemiJoinOperator:        public SemiJoinPages(SetSupplier channelSetFuture, int probeJoinChannel, Optional<Integer> probeHashChannel, AggregatedMemoryContext aggregatedMemoryContext)
        {
            checkArgument(probeJoinChannel >= 0, "probeJoinChannel is negative");

            this.channelSetFuture = requireNonNull(channelSetFuture, "hashProvider is null").getChannelSet();
            this.probeJoinChannel = probeJoinChannel;
            this.probeHashChannel = requireNonNull(probeHashChannel, "hashChannel is null");
            this.localMemoryContext = requireNonNull(aggregatedMemoryContext, "aggregatedMemoryContext is null").newLocalMemoryContext(SemiJoinPages.class.getSimpleName());
        }