code: private void unclaim(String subscription, Collection<EventList> eventLists) {
          List<String> eventIdsToUnclaim = Lists.newArrayList();
          for (EventList unclaimEvents : eventLists) {
              for (Pair<String, UUID> eventAndChangeId : unclaimEvents.getEventAndChangeIds()) {
                  eventIdsToUnclaim.add(eventAndChangeId.first());
              }
          }
          _eventStore.renew(subscription, eventIdsToUnclaim, Duration.ZERO, false);
  
      }
docs: Convenience method to unclaim all of the events from a collection of event lists.  This is to unclaim excess
  events when a padded poll returns more events than the requested limit.