docs: @BetaApi(
        "The surface for long-running operations is not stable yet and may change in the future.")
    public final OperationFuture<Cluster, ClusterOperationMetadata> updateClusterAsync(
        String projectId, String region, String clusterName, Cluster cluster, FieldMask updateMask) {
  
      UpdateClusterRequest request =
          UpdateClusterRequest.newBuilder()
              .setProjectId(projectId)
              .setRegion(region)
              .setClusterName(clusterName)
              .setCluster(cluster)
              .setUpdateMask(updateMask)
              .build();
      return updateClusterAsync(request);
    }