Scala function serialization

fn.scala

import java.io._

object Main {
  def main(args: Array[String]): Unit = {
    val stream = new ByteArrayOutputStream()
    val out = new ObjectOutputStream(stream)

    def foo(): String => String = {
      val test = "hello"
      def bar(name: String): String = s"$test $name"
      bar
    }

    out.writeObject(foo())
    out.close()

    val bytes = stream.toByteArray
    val in = new ObjectInputStream(new ByteArrayInputStream(bytes))
    val fn: String => String = in.readObject().asInstanceOf[String => String]

    println(fn("world"))
  }
}