message: billing platform - accountData optional
diff: @@ -88,7 +88,7 @@ export interface BillingInvoiceItem {
  transactionID: number;
  currency: string;
  pricingData: PricedConsumptionData[]
  - accountData: BillingSessionAccountData; // Each session may target a distinct sub-account - but the 4 pricing dimensions MUST share the same info
  + accountData?: BillingSessionAccountData; // Each session may target a distinct sub-account - but the 4 pricing dimensions MUST share the same info
  headerDescription?: string,
  metadata?: {
  // Just a flat list of key/value pairs!
  @@ -99,7 +99,7 @@ export interface BillingInvoiceItem {
  export interface BillingSessionData {
  transactionID: number;
  pricingData: PricedConsumptionData[];
  - accountData: BillingSessionAccountData; // Each session may target a distinct sub-account
  + accountData?: BillingSessionAccountData; // Each session may target a distinct sub-account
  }
  export enum BillingInvoiceStatus {
  