Scala serialization issue, pickling library.

SerializationTest.scala

import java.io.{ByteArrayInputStream, ByteArrayOutputStream, ObjectInputStream, ObjectOutputStream}
import scala.pickling.Defaults._, scala.pickling.binary._

object Main extends App {
  SerializationTest.run()
}

case class IntSeqHolder(seq: Seq[Int])

case class Pupper(name: String)

case class Doggies(oldPuppers: Seq[Pupper])

object SerializationTest {

  def run() {
    val data = Seq(
      Seq(1),
      IntSeqHolder(Seq(1)),
      Seq(Some(1)),
      Seq(Pupper("Collin")),
      Doggies(Seq(Pupper("Adolf"), Pupper("Ben")))
    )
    val runners = Seq(
      ("classic", testClassic _),
      ("pickling", testPickling _)
    )

    for {x <- data} {
      println(s"-- Running tests with data $x.")
      println()
      for {(runnerName, fn) <- runners} {
        println(s"Using $runnerName on $x")
        try {
          val (res, serialized) = fn(x)
          println(s"$x ==> ${serialized.length} B ==> $res")
          assert(x == res)
          println(s"Test succeeded.")
        } catch {
          case e: Throwable =>
            println(s"Test failed: ${e.getClass.getSimpleName} - ${e.getMessage}")
            e.printStackTrace()
        }
        println()
      }
      println()
    }
  }

  def testClassic(input: AnyRef): (AnyRef, Array[Byte]) = {
    val serialized = {
      val bos = new ByteArrayOutputStream()
      val out = new ObjectOutputStream(bos)
      out.writeObject(input)
      val r = bos.toByteArray
      out.close()
      bos.close()
      r
    }
    val unserialized = {
      val bis = new ByteArrayInputStream(serialized)
      val in = new ObjectInputStream(bis)
      val r = in.readObject()
      in.close()
      bis.close()
      r
    }
    (unserialized, serialized)
  }

  def testPickling(input: AnyRef): (AnyRef, Array[Byte]) = {
    val pickled: Array[Byte] = input.pickle.value
    (pickled.unpickle[AnyRef], pickled)
  }
}