WebhookSubscriptionModel constructor
      const
      WebhookSubscriptionModel({ 
    
    
- required String id,
 - required String callbackUrl,
 - required WebhookOperation eventType,
 - required ExtApiV2DataType dataType,
 - required DateTime expirationTime,
 
Implementation
const WebhookSubscriptionModel({
  required this.id,
  required this.callbackUrl,
  required this.eventType,
  required this.dataType,
  required this.expirationTime,
});