code: public static ApruveResponse<SubscriptionCancelResponse> cancel(
  			String subscriptionId) {
  		return ApruveClient.getInstance().post(getCancelPath(subscriptionId),
  				"", SubscriptionCancelResponse.class);
  	}
docs: Cancels the Subscription with the given ID. This cannot be undone once
  completed, so use with care!
  
  @see <a
  href="https://www.apruve.com/doc/developers/rest-api/">https://www.apruve.com/doc/developers/rest-api/</a>
  @return SubscriptionCancelResponse