code: public Cluster getCluster(String clusterId, String zoneId) {
      Cluster response = null;
      for (Cluster cluster : getClusters().getClustersList()) {
        if (cluster.getName().endsWith("/clusters/" + clusterId)
            && cluster.getLocation().endsWith("/locations/" + zoneId)) {
          if (response == null) {
            response = cluster;
          } else {
            throw new IllegalStateException(
                String.format("Got multiple clusters named %s in zone %z.", clusterId, zoneId));
          }
        }
      }
      return Preconditions.checkNotNull(response,
        String.format("Cluster %s in zone %s was not found.", clusterId, zoneId));
    }
docs: Gets the current configuration of the cluster as encapsulated by a {@link Cluster} object.
  
  @param clusterId
  @param zoneId
  @return the {@link Cluster} if it was set. If the cluster is not found, throw a {@link
  NullPointerException}.