code: public static String getElasticSearchAddDocument(Map<String, String> values) {
      StringBuilder builder = new StringBuilder();
      builder.append("{");
      boolean first = true;
      for (Map.Entry<String, String> pair : values.entrySet()) {
        if (!first) {
          builder.append(",");
        }
        JSONUtils.addElasticSearchField(builder, pair);
        first = false;
      }
      builder.append("}");
      return builder.toString();
    }
docs: Returns ElasticSearch add command.
  
  @param values
  values to include
  @return XML as String