presto-main/src/main/java/io/prestosql/operator/LookupJoinOperator.java/LookupJoinOperator/SpillInfoSnapshot
class LookupJoinOperator:        public SpillInfoSnapshot(boolean hasSpilled, long spillEpoch, IntPredicate spillMask)
        {
            this.hasSpilled = hasSpilled;
            this.spillEpoch = spillEpoch;
            this.spillMask = requireNonNull(spillMask, "spillMask is null");
        }