code: public SubscriptionEnvelope createSubscription(SubscriptionInfo subscriptionInfo) throws ApiException {
          ApiResponse<SubscriptionEnvelope> resp = createSubscriptionWithHttpInfo(subscriptionInfo);
          return resp.getData();
      }
docs: Create Subscription
  Create Subscription
  @param subscriptionInfo Subscription details (required)
  @return SubscriptionEnvelope
  @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body