anchor.diff:      Key key,
       this.animating = true,
       this.radius = _kDefaultIndicatorRadius,
  -    @Deprecated(
  -      'Leave this field default to use latest style. '
  -      'This feature was deprecated after v1.21.0-1.0.pre.'
  -    )
  -    this.iOSVersionStyle = CupertinoActivityIndicatorIOSVersionStyle.iOS14,
     })  : assert(animating != null),
           assert(radius != null),
           assert(radius > 0.0),
  
positive.code:     Key key,
      this.radius = _kDefaultIndicatorRadius,
      this.progress = 1.0,
      @Deprecated(
        'Leave this field default to use latest style. '
        'This feature was deprecated after v1.21.0-1.0.pre.'
      )
      this.iOSVersionStyle = CupertinoActivityIndicatorIOSVersionStyle.iOS14,
    })  : assert(radius != null),
          assert(radius > 0.0),
          assert(progress != null),
  
negative.code:     @required this.activeColor,
      @required this.radius,
      @required this.progress,
    })  : tickFundamentalRRect = RRect.fromLTRBXY(
            -radius / _kDefaultIndicatorRadius,
            -radius / 3.0,
            radius / _kDefaultIndicatorRadius,
            -radius,
            radius / _kDefaultIndicatorRadius,
  