@type t() :: %Rapyd.Types.Subscription{
  billing: String.t() | nil,
  canceled_at: integer() | nil,
  current_period_end: integer() | nil,
  current_period_start: integer() | nil,
  customer: String.t(),
  days_until_due: integer(),
  default_payment_method: String.t() | nil,
  id: String.t(),
  metadata: map() | nil,
  plan: Rapyd.Types.Plan.t() | nil,
  status: String.t(),
  tax_percent: float(),
  trial_end: integer() | nil,
  trial_start: integer() | nil
}