shape_border library Null safety

Based on the ShapeBorder class in the Flutter SDK.

Classes

BeveledRectangleBorder
Border
BorderDirectional
BoxBorder
Based on the BoxBorder class in the Flutter SDK.
CircleBorder
ContinuousRectangleBorder
InputBorder
Based on the InputBorder class in the Flutter SDK.
InputBorderNone
OutlinedBorder
Based on the OutlinedBorder class in the Flutter SDK.
OutlineInputBorder
OvalBorder
RoundedRectangleBorder
ShapeBorder
StadiumBorder
StarBorder
UnderlineInputBorder