docs: public boolean isConnected() {
          final Health request = new Health.Builder()
                  .local()
                  .timeout(Ints.saturatedCast(requestTimeout.toSeconds()))
                  .build();
  
          try {
              final JestResult result = JestUtils.execute(jestClient, request, () -> "Couldn't check connection status of Elasticsearch");
              final int numberOfDataNodes = result.getJsonObject().path("number_of_data_nodes").asInt();
              return numberOfDataNodes > 0;
          } catch (ElasticsearchException e) {
              if (LOG.isDebugEnabled()) {
                  LOG.error(e.getMessage(), e);
              }
              return false;
          }
      }