code: protected NameResolver<InetAddress> newNameResolver(EventLoop eventLoop,
                                                          ChannelFactory<? extends DatagramChannel> channelFactory,
                                                          DnsServerAddressStreamProvider nameServerProvider)
              throws Exception {
          // once again, channelFactory and nameServerProvider are most probably set in builder already,
          // but I do reassign them again to avoid corner cases with override methods
          return dnsResolverBuilder.eventLoop(eventLoop)
                  .channelFactory(channelFactory)
                  .nameServerProvider(nameServerProvider)
                  .build();
      }
docs: Creates a new {@link NameResolver}. Override this method to create an alternative {@link NameResolver}
  implementation or override the default configuration.