docs: public static @Nullable String get(@NotNull Map<String, String[]> requestMap, @NotNull String param) {
      String value = null;
      String[] valueArray = requestMap.get(param);
      if (valueArray != null && valueArray.length > 0) {
        value = valueArray[0];
      }
      // convert encoding to UTF-8 if not form encoding parameter is set
      if (value != null && !hasFormEncodingParam(requestMap)) {
        value = convertISO88591toUTF8(value);
      }
      return value;
    }