anchor.diff:  /// A representation of distances for each of the four edges of a rectangle,
   /// used to encode the view insets and padding that applications should place
   /// around their user interface, as exposed by [Window.viewInsets] and
  -/// [Window.padding]. View insets and padding are preferrably read via
  +/// [Window.padding]. View insets and padding are preferably read via
   /// [MediaQuery.of].
   ///
   /// For a generic class that represents distances around a rectangle, see the
  
positive.code:   /// in the foreground inactive state.  Apps transition to this state when
    /// another activity is focused, such as a split-screen app, a phone call,
    /// a picture-in-picture app, a system dialog, or another window.
    /// 
    /// Apps in this state should assume that they may be [paused] at any time.
    inactive,
  
  
negative.code: 
    /// A window padding that has zeros for each edge.
    static const WindowPadding zero = const WindowPadding._(left: 0.0, top: 0.0, right: 0.0, bottom: 0.0);
  
    @override
    String toString() {
      return '$runtimeType(left: $left, top: $top, right: $right, bottom: $bottom)';
    }
  }
  
  /// An identifier used to select a user's language and formatting preferences,
  