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1. KeyValueMapper<K, V, I> idExtractor — extracts a unique identifier from a record by which we de-duplicate input records. If it returns null, the record will not be considered for de-duping and forwarded as-is. If not provided, defaults to (key, value) -> key, which means deduplication based on key of the record. Important assumption: records from different partitions should have different IDs, otherwise same IDs might be not co-partitioned.
2. TimeWindows timeWindows — tumbling or hopping time-based window specification. Required parameter. Only the first message with a given id that falls into a window will be passed downstream.
3. Serde<I> idSerde — serde for unique identifier.
4. boolean isPersistent — whether the WindowStore that stores the unique ids should be persistent or not. In many cases, non-persistent store will be preferrable, since downstream consumers should be ready to accept duplicates sometimes.

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