code: public SubscriptionEnvelope deleteSubscription(String subId) throws ApiException {
          ApiResponse<SubscriptionEnvelope> resp = deleteSubscriptionWithHttpInfo(subId);
          return resp.getData();
      }
docs: Delete Subscription
  Delete Subscription
  @param subId Subscription ID. (required)
  @return SubscriptionEnvelope
  @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body