code: private static Optional<Map.Entry<String, String>> createTagEntry(Map.Entry<String, MetricValue> tag_entry) {
          final Optional<String> opt_tag_value = tag_entry.getValue().asString();
          return opt_tag_value
                  .map(tag_value -> SimpleMapEntry.create(name(tag_entry.getKey()), escapeTagValue(tag_value)));
      }
docs: Transform a tag entry into a wavefront tag.
  
  Double quotes in the tag value will be escaped.