``` .flatMap(response -> { ...

# announcements

[ursus]

.flatMap(response -> {
                    if (!response.isSuccessful()) {
                        ResponseBody errorBody = response.errorBody();
                        if (errorBody == null) {
                            return Single.error(new IllegalStateException("Error response body is null"));
                        }
                    }
                    return Single.just(response);
                });