hr_fraud.scala

case class Order(val id: Int, val card: Int, val address: String)

// val m = (for (i <- 1 to 4) yield Order(i)) zip List(1, 1, 2, 3)
// m.groupBy(_._2)

val orders = (for {
  order <- List(Order(1, 46459, "3, calle Brazil, Torremolinos"),
                Order(2, 85475, "102, av JB Clement, Boulogne"),
                Order(1, 78545, "1, Paradize Bvld., Palo Alto"))
} yield (order, order.id))

orders.groupBy(_._2).filter(_._2.length > 1)