code: @Override
      public void setTrafficClass(int trafficClass) {
          try {
              channel.socket().setTrafficClass(trafficClass);
          } catch (SocketException e) {
              throw new RuntimeIoException(e);
          }
      }
docs: {@inheritDoc}
  @throws RuntimeIoException If the socket is closed or if we get an
  {@link SocketException}