Positioned.fill constructor Null safety
Creates a Positioned object with left, top, right, and bottom set to 0.0 unless a value for them is passed.
Implementation
const Positioned.fill({
super.key,
this.left = 0.0,
this.top = 0.0,
this.right = 0.0,
this.bottom = 0.0,
required super.child,
}) : width = null,
height = null;