static byte[] getBytes(ClassicHttpResponse response) {
        try {
            return response.getEntity() == null ? null : EntityUtils.toByteArray(response.getEntity());
        }
        catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }
Reads the response body, throwing an {@link UncheckedIOException} if this fails, or {@code null} if there is none.
http-client/src/main/java/ai/vespa/hosted/client/HttpClient.java