code: private Observable<ProposedBucketConfigContext> refreshAgainstNode(final String bucketName, final NetworkAddress hostname) {
          return Buffers.wrapColdWithAutoRelease(Observable.defer(new Func0<Observable<GetBucketConfigResponse>>() {
              @Override
              public Observable<GetBucketConfigResponse> call() {
                  return cluster().send(new GetBucketConfigRequest(bucketName, hostname));
              }
          }))
          .doOnNext(new Action1<GetBucketConfigResponse>() {
              @Override
              public void call(GetBucketConfigResponse response) {
                  if (!response.status().isSuccess()) {
                      if (response.content() != null && response.content().refCnt() > 0) {
                          response.content().release();
                      }
                      throw new ConfigurationException("Could not fetch config from node: " + response);
                  }
              }
          })
          .map(new Func1<GetBucketConfigResponse, ProposedBucketConfigContext>() {
              @Override
              public ProposedBucketConfigContext call(GetBucketConfigResponse response) {
                  String raw = response.content().toString(CharsetUtil.UTF_8).trim();
                  if (response.content().refCnt() > 0) {
                      response.content().release();
                  }
  
                  raw = raw.replace("$HOST", response.hostname().address());
                  return new ProposedBucketConfigContext(bucketName, raw, hostname);
              }
          })
          .doOnError(new Action1<Throwable>() {
              @Override
              public void call(Throwable ex) {
                  LOGGER.debug("Could not fetch config from bucket \"" + bucketName + "\" against \""
                          + hostname + "\".", ex);
              }
          });
      }
docs: Helper method to fetch a config from a specific node of the cluster.
  
  @param bucketName the name of the bucket.
  @param hostname the hostname of the node to fetch from.
  @return a raw configuration or an error.