docs: public static <K extends Comparable<K>, V> void toStringSorted(Map<K, V> map, StringBuilder builder) {
      builder.append("{");
      List<Entry<K,V>> sortedProperties = Maps.sortedEntries(map);
      int index = 0;
      for (Entry<K, V> entry : sortedProperties) {
        if (index > 0) {
          builder.append(", ");
        }
        builder.append(entry.getKey()).append("=").append(entry.getValue());
        index++;
      }
      builder.append("}");
    }