private String createImportedLabelId(TokensAndUrlAuthData authData, String labelName)
      throws IOException {
    Label newLabel =
        new Label()
            .setName(labelName)
            .setLabelListVisibility("labelShow")
            .setMessageListVisibility("show");
    return getOrCreateGmail(authData).users().labels().create(USER, newLabel).execute().getId();
  }
Creates the given {@code labelName} in the import service provider and returns the id.
extensions/data-transfer/portability-data-transfer-google/src/main/java/org/datatransferproject/datatransfer/google/mail/GoogleMailImporter.java