code: public Subscription update( Subscription subscription ) {
      return RestfulUtils.update( SubscriptionService.PATH, subscription, Subscription.class, super.httpClient );
    }
docs: Updates a subscription.<br>
  <br>
  Following fields will be updated:<br>
  <br>
  <ul>
  <li>interval (note, that nextCaptureAt will not change.)
  <li>currency
  <li>name
  <li>payment
  </ul>
  <br>
  To update further properties of a subscription use following methods:<br>
  <br>
  <ul>
  <li>{@link SubscriptionService#cancel(Subscription)} to cancel
  <li>{@link SubscriptionService#changeAmount(Subscription, Integer)} to change the amount
  <li>{@link SubscriptionService#changeOfferChangeCaptureDateAndRefund(Subscription, Offer)} to change the offer.
  <li>{@link SubscriptionService#changeOfferKeepCaptureDateAndRefund(Subscription, Offer)} to change the offer.
  <li>{@link SubscriptionService#changeOfferKeepCaptureDateNoRefund(Subscription, Offer)} to change the offer.
  <li>{@link SubscriptionService#endTrial(Subscription)} to end the trial
  <li>{@link SubscriptionService#limitValidity(String, com.paymill.models.Interval.Period)} to limit the validity.
  <li>{@link SubscriptionService#pause(Subscription)} to pause
  <li>{@link SubscriptionService#unlimitValidity(Subscription)} to change the validity.
  <li>{@link SubscriptionService#unpause(Subscription)} to unpause.
  </ul>
  <p>
  
  @param subscription A {@link Subscription} with Id to be updated.
  @return the updated subscription