Spark Cassandra Connector Enum fiasco

CassandraEnum.scala

import org.apache.spark.{SparkConf, SparkContext}

import com.datastax.spark.connector._
import com.datastax.spark.connector.types._
import scala.reflect.runtime.universe._

object Days {
  sealed abstract class WeekDay(val id: Int)

  object WeekDay {
    val intMapping = Map(0 -> MON, 1 -> TUE, 2 -> WED, 3 -> THU, 4 -> FRI, 5 -> SAT, 6 -> SUN)
    val stringMapping = Map("MON" -> MON, "TUE" -> TUE, "WED" -> WED, "THU" -> THU, "FRI" -> FRI, "SAT" -> SAT, "SUN" -> SUN)

    def apply(id: Int) = intMapping.getOrElse(id, MON)
    def apply(id: String) = stringMapping.getOrElse(id, MON)
    
    def unapply(id: Int): Option[Int] = Option(id)
  }

  case object MON extends WeekDay(0)
  case object TUE extends WeekDay(1)
  case object WED extends WeekDay(2)
  case object THU extends WeekDay(3)
  case object FRI extends WeekDay(4)
  case object SAT extends WeekDay(5)
  case object SUN extends WeekDay(6)
}
import Days._

object Example {

  object IntToWeekDayConverter extends TypeConverter[WeekDay] {
    def targetTypeTag = typeTag[WeekDay]
    def convertPF = { case i: Int => WeekDay(i) }
  }

  object WeekDayToIntConverter extends TypeConverter[Integer] {
    def targetTypeTag = typeTag[Integer]
    def convertPF = { case wd: WeekDay => wd.id }
  }

  case class MyCassandraRow(id: String, weight: Int, day: WeekDay)

  def main (args: Array[String]) {

    TypeConverter.registerConverter(IntToWeekDayConverter)
    TypeConverter.registerConverter(WeekDayToIntConverter)

    val conf = new SparkConf()
      .setAppName("cassandra-connector-example")
      .set("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
      .set("spark.cassandra.connection.host", "127.0.0.1")
      .setMaster("local[*]")
    val sc = new SparkContext(conf)

    val data = sc.parallelize(
      Seq(
        MyCassandraRow("identifier1", 10, MON),
        MyCassandraRow("identifier2", 20, FRI),
        MyCassandraRow("identifier3", 1, SUN)
      )
    )

    data.saveToCassandra("db", "custom_data")

    val readData = sc.cassandraTable[MyCassandraRow]("db", "custom_data")
      .collect()
      .foreach(println)
  }
}

database.sql

DROP KEYSPACE IF EXISTS db;
CREATE KEYSPACE db WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };

use db;

create table custom_data (
    id text,
    weight int,
    day int,
    primary key(id)
);