@type t() :: %DocuSign.Model.BillingPlanUpdateResponse{
  accountPaymentMethod: String.t() | nil,
  billingPlanPreview: DocuSign.Model.BillingPlanPreview.t() | nil,
  currencyCode: String.t() | nil,
  includedSeats: String.t() | nil,
  paymentCycle: String.t() | nil,
  paymentMethod: String.t() | nil,
  planId: String.t() | nil,
  planName: String.t() | nil
}