shape property Null safety
final
Default value for SnackBar.shape.
If null, SnackBar provides different defaults depending on the SnackBarBehavior. For SnackBarBehavior.fixed, no overriding shape is specified, so the SnackBar is rectangular. For SnackBarBehavior.floating, it uses a RoundedRectangleBorder with a circular corner radius of 4.0.
Implementation
final ShapeBorder? shape;