private HttpRequest.Builder createMusicImportRequest(URI url, byte[] body) {
        HttpRequest.Builder requestBuilder = createBaseRequestBuilder(url);
        return requestBuilder
                .POST(HttpRequest.BodyPublishers.ofByteArray(body))
                .header("Content-Type", "application/x-protobuf");
    }
@return the total number of playlist tracks acknowledged by the Apple Music Library Service in this page
extensions/data-transfer/portability-data-transfer-apple/src/main/java/org/datatransferproject/datatransfer/apple/music/AppleMusicInterface.java