public static <K, V> Produced<K, V> keySerde(final Serde<K> keySerde) {
        return new Produced<>(keySerde, null, null, null);
    }
Create a Produced instance with provided keySerde.
@param keySerde      Serde to use for serializing the key
@param <K>           key type
@param <V>           value type
@return  A new {@link Produced} instance configured with keySerde
@see KStream#to(String, Produced)
streams/src/main/java/org/apache/kafka/streams/kstream/Produced.java