FractionallySizedBoxModifier constructor
      const
      FractionallySizedBoxModifier({ 
    
- Key? key,
- Widget? child,
- AlignmentGeometry alignment = Alignment.center,
- double? widthFactor,
- double? heightFactor,
Creates a widget that sizes its child to a fraction of the total available space.
If non-null, the widthFactor and heightFactor arguments must be
non-negative.
Implementation
const FractionallySizedBoxModifier({
  super.key,
  super.child,
  this.alignment = Alignment.center,
  this.widthFactor,
  this.heightFactor,
})  : assert(widthFactor == null || widthFactor >= 0.0),
      assert(heightFactor == null || heightFactor >= 0.0);