anchor.diff:        {Key key,
         this.width,
         this.height,
  +      this.fit = BoxFit.contain,
  +      this.alignment = Alignment.center,
         this.matchTextDirection = false,
         this.allowDrawingOutsideViewBox = false,
         this.placeholderBuilder})
  
positive.code:   ///
    /// The [bytes] argument must not be null.
    ///
    /// If `width` or `height` are specified, a [SizedBox] will be used to dictate
    /// the width and height of the rendered output.  Otherwise, the picture will
    /// be sized to its parent.
    ///
    /// If `matchTextDirection` is set to true, the picture will be flipped
    /// horizontally in [TextDirection.rtl] contexts.
  
negative.code:   ///
    /// The [bytes] argument must not be null.
    ///
    /// Either the [width] and [height] arguments should be specified, or the
    /// widget should be placed in a context that sets tight layout constraints.
    /// Otherwise, the image dimensions will change as the image is loaded, which
    /// will result in ugly layout changes.
    ///
    /// If `matchTextDirection` is set to true, the picture will be flipped
    /// horizontally in [TextDirection.rtl] contexts.
  