public Produced<K, V> withKeySerde(final Serde<K> keySerde) {
        this.keySerde = keySerde;
        return this;
    }
Produce records using the provided keySerde.
@param keySerde    Serde to use for serializing the key
@return this
streams/src/main/java/org/apache/kafka/streams/kstream/Produced.java