code: public static String formatSubscriptionPath(String topicPath, String subscriptionName) {
          return String.join(pathDelimiter, topicPath, subscriptionsSubPath, subscriptionName);
      }
docs: Formats the subscription path, based on the topic path and subscription name.
  @param topicPath - The name of the topic, including slashes.
  @param subscriptionName - The name of the subscription.
  @return The path of the subscription.