code: public static void sendMetric(String metric, int value, long ts, CloseableHttpClient httpClient, String url) throws IOException {
          sendMetric(null, metric, value, ts, httpClient, url);
      }
docs: Send the given value for the given metric and timestamp.
  
  Authentication can be provided via the configured {@link HttpClient} instance.
  
  @param metric The key of the metric
  @param value The value of the measurement
  @param ts The timestamp of the measurement
  @param httpClient The HTTP Client that can be used to send metrics.
  This can also contain credentials for basic authentication if necessary
  @param url The base URL where Elasticsearch is available.
  
  @throws IOException If the HTTP call fails with an HTTP status code.