SizeTransition constructor Null safety

const SizeTransition(
  1. {Key? key,
  2. Axis axis = Axis.vertical,
  3. required Animation<double> sizeFactor,
  4. double axisAlignment = 0.0,
  5. Widget? child}

Creates a size transition.

The axis, sizeFactor, and axisAlignment arguments must not be null. The axis argument defaults to Axis.vertical. The axisAlignment defaults to 0.0, which centers the child along the main axis during the transition.


const SizeTransition({
  this.axis = Axis.vertical,
  required Animation<double> sizeFactor,
  this.axisAlignment = 0.0,
}) : assert(axis != null),
     assert(sizeFactor != null),
     assert(axisAlignment != null),
     super(listenable: sizeFactor);