Sample for SO question https://stackoverflow.com/questions/1094173/how-do-i-get-around-type-erasure-on-scala-or-why-cant-i-get-the-type-paramete#21640639

SerializerAndPathDependentTypes.scala

package basics

import akka.actor.{ActorSystem, ExtendedActorSystem}
import akka.serialization.{JavaSerializer, SerializationExtension}
import com.typesafe.config.ConfigFactory

trait MyPayload
trait OtherPayload

trait PersistentExecutorProtocol extends Serializable {
  type Payload
  sealed trait Event extends Serializable
  sealed trait Todo { def value: Payload }
  final case class Done(value: Long) extends Event
}
object AProtocolInstance extends PersistentExecutorProtocol {
  type Payload = MyPayload
  final case class ToDo(value: MyPayload) extends super.Todo
}
object BProtocolInstance extends PersistentExecutorProtocol {
  type Payload = OtherPayload
  final case class ToDo(value: OtherPayload) extends super.Todo
}

class SerializerA(system: ExtendedActorSystem) extends JavaSerializer(system)
class SerializerB(system: ExtendedActorSystem) extends JavaSerializer(system)

object SerializerAndPathDependentTypes extends App {

  implicit val system = ActorSystem("sample", ConfigFactory.parseString(
    """
      akka.actor {
        serializers {
          serializerA = "basics.SerializerA"
          serializerB = "basics.SerializerB"
        }
        serialization-identifiers {
          "basics.SerializerA" = 70
          "basics.SerializerB" = 71
        }
        serialization-bindings {
          "basics.AProtocolInstance$ToDo" = serializerA
          "basics.BProtocolInstance$ToDo" = serializerB
        }
      }
    """))

  val ser = SerializationExtension(system)

  println("serializer for AProtocolInstance.ToDo: " + ser.serializerFor(classOf[AProtocolInstance.ToDo]).getClass)
  println("serializer for BProtocolInstance.ToDo: " + ser.serializerFor(classOf[BProtocolInstance.ToDo]).getClass)

}