anchor.diff:    /// widget instances when called. Avoid using a builder that returns a
     /// previously-constructed widget; if the list view's children are created in
     /// advance, or all at once when the [ListView] itself is created, it is more
  -  /// efficient to use [new ListView].
  +  /// efficient to use the [ListView] constructor.
     ///
     /// {@tool snippet}
     ///
  
positive.code:   ///
    /// See also:
    ///
    ///  * [new SliverGrid.extent], the equivalent constructor for [SliverGrid].
    GridView.extent({
      Key key,
      Axis scrollDirection = Axis.vertical,
  
negative.code:   /// child that could possibly be displayed in the list view instead of just
    /// those children that are actually visible.
    ///
    /// It is usually more efficient to create children on demand using
    /// [ListView.builder].
    ///
    /// The `addAutomaticKeepAlives` argument corresponds to the
    /// [SliverChildListDelegate.addAutomaticKeepAlives] property. The
  