Drummer2.scala

object Domain { 
 
  case class Drummer private (name:String) { 
      def copy() = Drummer(name) 
  } 
 
  object Drummer { 
    def apply(name:String) = 
      List("Max Roache", "Tony Williams", "Elvin Jones").find(_ == name).map(new Drummer(_)) 
  } 
}