RecommendAFriendFunctionDeps1.scala

object RecommendAFriend{
  def apply(validate: NewAccountDetails => Unit, findCustomer: String => Option[User], 
            createCustomer: NewAccountDetails => User, referralPolicy: (User, User) => Future[Unit])
            (referrerId: Int, friendsAccountDetails: NewAcccountDetails) = {
    validate(friendsAccountDetails)
    
    val user = findCustomer(referrerId);
    val friend = createCustomer(friendsAccountDetails)
    referralPolicy(user, friend)
  }
}