@type t() :: %Rapyd.Types.Plan{
  active: boolean(),
  amount: float(),
  created_at: integer(),
  currency: String.t(),
  id: String.t(),
  interval: String.t(),
  interval_count: integer(),
  metadata: map() | nil,
  nickname: String.t() | nil,
  product_id: String.t() | nil,
  trial_period_days: integer()
}