@type t() :: %Polarex.ListResourceDiscount{
  items: [
    Polarex.DiscountFixedOnceForeverDuration.t()
    | Polarex.DiscountFixedRepeatDuration.t()
    | Polarex.DiscountPercentageOnceForeverDuration.t()
    | Polarex.DiscountPercentageRepeatDuration.t()
  ],
  pagination: Polarex.Pagination.t()
}