@Nullable
  public String completeUpload() throws AppleContentException {
    try {
      try {
        StringBuilder content;
        try (BufferedReader br =
            new BufferedReader(new InputStreamReader(connection.getInputStream()))) {
          String line;
          content = new StringBuilder();
          while ((line = br.readLine()) != null) {
            content.append(line);
            content.append(System.lineSeparator());
          }
        }
        return content.toString();
      } finally {
        connection.disconnect();
      }
    } catch (IOException e) {
      monitor.severe(() -> "Error when completing upload", e);
      connection.disconnect();
      throw new AppleContentException("Error when uploading to Content", e);
    }
  }
Uploads the given bytes to the url specified in the constructor. If lastRequest is true, the
upload is complete and a ContentResponse is returned. Otherwise, null is returned.

@param uploadBytes
@return ContentResponse
@throws AppleContentException
extensions/data-transfer/portability-data-transfer-apple/src/main/java/org/datatransferproject/datatransfer/apple/photos/streaming/StreamingContentClient.java