code: @SuppressWarnings("WeakerAccess")
    public List<Cluster> listClusters(String instanceId) {
      return ApiExceptions.callAndTranslateApiException(listClustersAsync(instanceId));
    }
docs: Lists all clusters in the specified instance.
  
  <p>This method will throw a {@link PartialListClustersException} when any zone is unavailable.
  If partial listing are ok, the exception can be caught and inspected.
  
  <p>Sample code:
  
  <pre>{@code
  try {
  List<Cluster> clusters = client.listClusters("my-instance");
  } catch (PartialListClustersException e) {
  System.out.println("The following zones are unavailable: " + e.getUnavailableZones());
  System.out.println("But the following clusters are reachable: " + e.getClusters())
  }
  }</pre>