VersionDummy.scala

package com.scalaRethinkdb

object VersionDummy {
  trait Version extends Wire {
    val fromWire = (str: String) => str match {
      case "V0_3" => V0_3
      case "V0_4" => V0_4
      case _ => throw new RethinkDbUnexpectedResponseError("Some error.")
    }
  }

  case object V0_3 extends Version {
    val toWire = 0x5f75e83e
  }
  
  case object V0_4 extends Version {
    val toWire = 0x400c2d20
  }
}

Wire.scala

package com.scalaRethinkdb

trait Wire {
  type FromWire[T] = (String) => T

  val toWire: Int
  val fromWire: FromWire[T]
}