code: private void waitForHealthyCluster() throws Exception {
          Map<String, String> params = new HashMap<>();
          params.put("wait_for_status", this.clusterHealthColor);
          params.put("timeout", "30s");
  
          elasticSearchAdminClient.performRequest("GET", "/_cluster/health", params);
      }
docs: Waits for the ES cluster to become green.
  @throws Exception If there is an issue connecting with the ES cluster.