Response.protocolVersoin may be null causing NPEs

[edudar]

Response constructor does not indicate that protocolVersion can be null (I think it'd be good to use at least some version of @Nullable instead of a comment)

  private Response(Builder builder) {
    ...
    this.reason = builder.reason; // nullable
    this.headers = caseInsensitiveCopyOf(builder.headers);
    this.body = builder.body; // nullable
    this.protocolVersion = builder.protocolVersion;
  }

and it's used with no null checks here

  @Override
  public String toString() {
    StringBuilder builder =
        new StringBuilder(protocolVersion.toString()).append(" ").append(status);
    ...
  }

It can be null, however:

feign.okhttp.OkHttpClient {
  toFeignResponse() {
    return feign.Response.builder()
        .protocolVersion(enumForName(ProtocolVersion.class, response.protocol()))
  }

here, enumForName may return null, causing NPE down the line.

  public static <T extends Enum<?>> T enumForName(Class<T> enumClass, Object object) {
    String name = (nonNull(object)) ? object.toString() : null;
    for (T enumItem : enumClass.getEnumConstants()) {
      if (enumItem.name().equalsIgnoreCase(name) || enumItem.toString().equalsIgnoreCase(name)) {
        return enumItem;
      }
    }
    return null;
  }