code: public Subscription changeAmountTemporary( String subscriptionId, Integer amount ) {
      return this.changeAmountTemporary( new Subscription( subscriptionId ), amount );
    }
docs: Changes the amount of a subscription.<br>
  <br>
  The new amount is valid one-time only after which the original subscription amount will be charged again. If you
  want to permanently change the amount use {@link SubscriptionService#changeAmount(String, Integer)}.
  
  @param subscriptionId the Id of the subscription.
  @param amount the new amount.
  @return the updated subscription.