function createDialog(domHelper) {
  const dialog = new AbstractDialog(domHelper);
  /** @suppress {visibility} suppression added to enable type checking */
  dialog.createDialogControl = () => new AbstractDialog.Builder(dialog).build();
  return dialog;
}
Creates a concrete instance of AbstractDialog by adding
a plain implementation of createDialogControl().
@param {dom.DomHelper} domHelper The dom helper to be used to create the
    dialog.
@return {!AbstractDialog} The created dialog.