anchor.diff:    /// If [snap] is true then a scroll that exposes the app bar will trigger an
     /// animation that slides the entire app bar into view. Similarly if a scroll
     /// dismisses the app bar, the animation will slide it completely out of view.
  +  ///
  +  /// ## Animated Examples
  +  ///
  +  /// The following animations show how the app bar changes its scrolling
  +  /// behavior based on the value of this property.
  +  ///
  +  /// * App bar with [floating] set to false:
  +  ///   {@animation 476 400 https://flutter.github.io/assets-for-api-docs/assets/material/app_bar.mp4}
  +  /// * App bar with [floating] set to true:
  +  ///   {@animation 476 400 https://flutter.github.io/assets-for-api-docs/assets/material/app_bar_floating.mp4}
  +  ///
  +  /// See also:
  +  ///
  +  /// * [SliverAppBar] for more animated examples of how this property changes the
  +  ///   behavior of the app bar in combination with [pinned] and [snap].
     final bool floating;
   
     /// Whether the app bar should remain visible at the start of the scroll view.
     ///
     /// The app bar can still expand and contract as the user scrolls, but it will
     /// remain visible rather than being scrolled out of view.
  +  ///
  +  /// ## Animated Examples
  +  ///
  +  /// The following animations show how the app bar changes its scrolling
  +  /// behavior based on the value of this property.
  +  ///
  +  /// * App bar with [pinned] set to false:
  +  ///   {@animation 476 400 https://flutter.github.io/assets-for-api-docs/assets/material/app_bar.mp4}
  +  /// * App bar with [pinned] set to true:
  +  ///   {@animation 476 400 https://flutter.github.io/assets-for-api-docs/assets/material/app_bar_pinned.mp4}
  +  ///
  +  /// See also:
  +  ///
  +  /// * [SliverAppBar] for more animated examples of how this property changes the
  +  ///   behavior of the app bar in combination with [floating].
     final bool pinned;
   
     /// If [snap] and [floating] are true then the floating app bar will "snap"
  
positive.code: /// )
  /// ```
  /// {@end-tool}
  ///
  /// See also:
  ///
  
negative.code:   ///
    /// Snapping only applies when the app bar is floating, not when the appbar
    /// appears at the top of its scroll view.
    ///
    /// ## Animated Examples
    ///
    /// The following animations show how the app bar changes its scrolling
    /// behavior based on the value of this property.
    ///
    /// * App bar with [snap] set to false:
    ///   {@animation 476 400 https://flutter.github.io/assets-for-api-docs/assets/material/app_bar_floating.mp4}
    /// * App bar with [snap] set to true:
    ///   {@animation 476 400 https://flutter.github.io/assets-for-api-docs/assets/material/app_bar_floating_snap.mp4}
    ///
    /// See also:
    ///
    /// * [SliverAppBar] for more animated examples of how this property changes the
    ///   behavior of the app bar in combination with [pinned] and [floating].
    final bool snap;
  
    @override
  