List<InstanceData> instances = computeServices.listInstances(auth, filterProject);
Map<Long, ReservationData> reservations = Maps.newHashMap();
ServerList response = new ServerList();
response.servers = Lists.newArrayList();
for (InstanceData instance : instances) {
ReservationData reservation = reservations.get(instance.getReservationId());
if (reservation == null) {
reservation = getReservation(instance.getReservationId());