docs: static void checkMetricAndTags(final String metric,
        final Map<String, String> tags) {
      if (tags.size() <= 0) {
        throw new IllegalArgumentException("Need at least one tag (metric="
            + metric + ", tags=" + tags + ')');
      } else if (tags.size() > Const.MAX_NUM_TAGS()) {
        throw new IllegalArgumentException("Too many tags: " + tags.size()
            + " maximum allowed: " + Const.MAX_NUM_TAGS() + ", tags: " + tags);
      }
  
      Tags.validateString("metric name", metric);
      for (final Map.Entry<String, String> tag : tags.entrySet()) {
        Tags.validateString("tag name with value [" + tag.getValue() + "]", 
            tag.getKey());
        Tags.validateString("tag value with key [" + tag.getKey() + "]", 
            tag.getValue());
      }
    }