code: <T> T callForJsonType(final String host, final int port, final String path,
        final List<Pair<String, String>> paramList, final Class<T> valueType) throws IOException {
      final String responseString = callForJsonString(host, port, path, paramList);
      if (null == responseString || responseString.length() == 0) {
        return null;
      }
      return new ObjectMapper().readValue(responseString, valueType);
    }
docs: Call executor and parse the JSON response as an instance of the class given as an argument.