ImmutableList.Builder<String> httpHeaders = ImmutableList.builder();
    for (Field field : httpHeadersFields()) {
      httpHeaders.add((String) field.get(null));
    }
    assertThat(httpHeaders.build()).containsNoDuplicates();
  }

  private static ImmutableSet<Field> httpHeadersFields() {
    ImmutableSet.Builder<Field> builder = ImmutableSet.builder();
    for (Field field : HttpHeaders.class.getDeclaredFields()) {
      /*

                Integer connectTimeout = null;
                Integer requestTimeout = null;

                PlexusConfiguration httpHeaders = config.getChild("httpHeaders", false);
                if (httpHeaders != null) {
                    PlexusConfiguration[] properties = httpHeaders.getChildren("property");
                    if (properties != null && properties.length > 0) {
                        headers = new HashMap<>();