* a valid value for V.
       */
      return uncheckedNull();
    } else {
      @SuppressWarnings("unchecked") // this is the only other option
      V asV = (V) obj;
      return asV;
    }
  }

  @Override
  public boolean isDone() {
    final Object localValue = value;
    return localValue != null & !(localValue instanceof SetFuture);

       * a valid value for V.
       */
      return uncheckedNull();
    } else {
      @SuppressWarnings("unchecked") // this is the only other option
      V asV = (V) obj;
      return asV;
    }
  }

  @Override
  public boolean isDone() {
    final Object localValue = value;
    return localValue != null & !(localValue instanceof SetFuture);

    // Plug the following UnicodeSet pattern into
    // https://unicode.org/cldr/utility/list-unicodeset.jsp
    // [[[:Zs:][:Zl:][:Zp:][:Cc:][:Cf:][:Cs:][:Co:]]&[\u0000-\uFFFF]]
    // with the "Abbreviate" option, and get the ranges from there.
    private static final String RANGE_STARTS =
        "\u0000\u007f\u00ad\u0600\u061c\u06dd\u070f\u0890\u08e2\u1680\u180e\u2000\u2028\u205f\u2066"
            + "\u3000\ud800\ufeff\ufff9";

    // transformEntries(map1, transformer);
    // transformEntries(map4, transformer);
    // transformEntries(map7, transformer);
  }

  public void testTransformEntriesExample() {
    Map<String, Boolean> options = ImmutableMap.of("verbose", true, "sort", false);
    EntryTransformer<String, Boolean, String> flagPrefixer =
        new EntryTransformer<String, Boolean, String>() {
          @Override

    // Plug the following UnicodeSet pattern into
    // https://unicode.org/cldr/utility/list-unicodeset.jsp
    // [[[:Zs:][:Zl:][:Zp:][:Cc:][:Cf:][:Cs:][:Co:]]&[\u0000-\uFFFF]]
    // with the "Abbreviate" option, and get the ranges from there.
    private static final String RANGE_STARTS =
        "\u0000\u007f\u00ad\u0600\u061c\u06dd\u070f\u0890\u08e2\u1680\u180e\u2000\u2028\u205f\u2066"
            + "\u3000\ud800\ufeff\ufff9";