code: public static int getPort(Config config, String path) {
          try {
              return new InetSocketAddress(config.getInt(path)).getPort();
          } catch (IllegalArgumentException e) {
              throw badValue(e, config, path);
          }
      }
docs: Get a port number.
  
  @param config a configuration object
  @param path the path expression
  @return a port number
  @throws ConfigException.Missing if the value is absent or null
  @throws ConfigException.WrongType if the value is not convertible to
  an integer
  @throws ConfigException.BadValue if the value is outside the port
  number range