void setPartitionTime(final long partitionTime) {
        this.partitionTime = partitionTime;
    }
RecordQueue is a FIFO queue of {@link StampedRecord} (ConsumerRecord + timestamp). It also keeps track of the
partition timestamp defined as the largest timestamp seen on the partition so far; this is passed to the
timestamp extractor.
streams/src/main/java/org/apache/kafka/streams/processor/internals/RecordQueue.java