code: public Optional<PartnerSubscription> create(long partnerId, long accountId, List<ProductSubscription> subscriptions)
      {
          return HTTP.POST(String.format("/v2/partners/%d/accounts/%d/subscriptions", partnerId, accountId), subscriptions, PARTNER_SUBSCRIPTION);
      }
docs: Raplaces the subscriptions on the account with the given subscriptions.
  @param partnerId The id of the partner the subscriptions belongs to
  @param accountId The id of the account for the subscriptions
  @param subscriptions The subscriptions to create
  @return The subscription that was created