Kafka Streams error

[Walter rakoff]

Hello,

I'm trying a sample Kafka Streams program in Scala.

    val clickRecordKStream: KStream[String, ClickRecord] =
      kStreamBuilder.stream(stringSerde, stringSerde, "test-topic")
      .map( (k:String, v:String) => (k, ClickRecord(v)))

The map call throws error "type mismatch; found : (String, String) =>
(String, ClickRecord) required:
org.apache.kafka.streams.kstream.KeyValueMapper[String,String,org.apache.kafka.streams.KeyValue[?,?]]

A similar example [1] has a comment " Requires a version of Scala that
supports Java 8 and SAM / Java lambda (e.g. Scala 2.11
with `-Xexperimental` compiler flag, or 2.12)"
Is there any way to get this working on Scala 2.10? Everything we write is
built in 2.10.
If not, what are the downside of `-Xexperimental` flag in 2.11?

[1]
https://github.com/confluentinc/examples/blob/master/kafka-streams/src/main/scala/io/confluent/examples/streams/MapFunctionScalaExample.scala

Thanks,
Walter