outerJoin

fun <K, V, otherV, outV> KTable<K, V>.outerJoin(other: KTable<K, otherV>, name: String? = null, materialized: Materialized<K, outV, KeyValueStore<Bytes, ByteArray>>? = null, joiner: ValueJoiner<V, otherV, outV>): KTable<K, outV>

See also