java.io.NotSerializableException using Apache Flink with Lagom

Question

I am writing Flink CEP program inside the Lagom's Microservice Implementation. My FLINK CEP program run perfectly fine in simple scala application. But when i use this code inside the Lagom service implementation i am receiving the following exception

Lagom Service Implementation

override def start =  ServiceCall[NotUsed, String] {

val env = StreamExecutionEnvironment.getExecutionEnvironment

var executionConfig = env.getConfig
env.setParallelism(1)
executionConfig.disableSysoutLogging()


var topic_name="topic_test"

var props= new Properties
props.put("bootstrap.servers", "localhost:9092")
props.put("acks","all");
props.put("key.serializer","org.apache.kafka.common.serialization.StringSerializer");
props.put("value.serializer","org.apache.kafka.common.serialization.ByteArraySerializer");
props.put("block.on.buffer.full","false");

val kafkaSource = new FlinkKafkaConsumer010 (topic_name, new KafkaDeserializeSchema , props)

val stream =  env.addSource(kafkaSource)


val deliveryPattern = Pattern.begin[XYZ]("begin").where(_.ABC == 5)
  .next("next").where(_.ABC == 10).next("end").where(_.ABC==5)

val deliveryPatternStream = CEP.pattern(stream, deliveryPattern)

def selectFn(pattern : collection.mutable.Map[String, XYZ]): String  = {
  val startEvent = pattern.get("begin").get
  val nextEvent = pattern.get("next").get
  "Alert Detected"


}

val deliveryResult =deliveryPatternStream.select(selectFn(_)).print()

env.execute("CEP")
req=> Future.successful("Done")

 }



}

I don't understand how to resolve this issue.