anchor.diff:    /// and iOS's VoiceOver provides an additional hint when the focused object is
     /// a button.
     static const SemanticsFlag isButton = SemanticsFlag._(_kIsButtonIndex);
  +
  +  /// Whether the semantic node represents a link.
  +  ///
  +  /// Platforms have special handling for links, for example, iOS's VoiceOver
  +  /// provides an additional hint when the focused object is a link.
  +  static const SemanticsFlag isLink = SemanticsFlag._(_kIsButtonIndex);
   
     /// Whether the semantic node represents a text field.
     ///
  
positive.code:     _kIsCheckedIndex: isChecked,
      _kIsSelectedIndex: isSelected,
      _kIsButtonIndex: isButton,
      _kIsTextFieldIndex: isTextField,
      _kIsFocusableIndex: isFocusable,
      _kIsFocusedIndex: isFocused,
  
negative.code:   static const int _kIsMultilineIndex = 1 << 19;
    static const int _kIsReadOnlyIndex = 1 << 20;
    static const int _kIsFocusableIndex = 1 << 21;
    static const int _kIsLinkIndex = 1 << 22;
  
    const SemanticsFlag._(this.index);
  
  