docs: private void queryMetrics(final MetricQueryServiceGateway queryServiceGateway) {
  		LOG.debug("Query metrics for {}.", queryServiceGateway.getAddress());
  
  		queryServiceGateway
  			.queryMetrics(timeout)
  			.whenCompleteAsync(
  				(MetricDumpSerialization.MetricSerializationResult result, Throwable t) -> {
  					if (t != null) {
  						LOG.debug("Fetching metrics failed.", t);
  					} else {
  						metrics.addAll(deserializer.deserialize(result));
  					}
  				},
  				executor);
  	}