*       }
   *     };
   * Map<String, String> transformed =
   *     Maps.transformEntries(options, flagPrefixer);
   * System.out.println(transformed);
   * }</pre>
   *
   * ... prints {@code {verbose=verbose, sort=nosort}}.
   *
   * <p>Changes in the underlying map are reflected in this view. Conversely, this view supports
   * removal operations, and these are reflected in the underlying map.
   *