code: public final HttpClient doOnResponseError(BiConsumer<? super HttpClientResponse, ? super Throwable> doOnResponse) {
  		Objects.requireNonNull(doOnResponse, "doOnResponse");
  		return new HttpClientDoOnError(this, null, doOnResponse);
  	}
docs: Setup a callback called when {@link HttpClientResponse} has not been fully
  received.
  
  @param doOnResponse a consumer observing response failures
  
  @return a new {@link HttpClient}