docs: public MetricName tagged(String... pairs) {
          if (pairs == null) {
              return this;
          }
  
          if (pairs.length % 2 != 0) {
              throw new IllegalArgumentException("Argument count must be even");
          }
  
          final Map<String, String> add = new HashMap<>();
  
          for (int i = 0; i < pairs.length; i += 2) {
              add.put(pairs[i], pairs[i+1]);
          }
  
          return tagged(add);
      }