behavior property Null safety
final
This defines the behavior and location of the snack bar.
Defines where a SnackBar should appear within a Scaffold and how its location should be adjusted when the scaffold also includes a FloatingActionButton or a BottomNavigationBar
If this property is null, then SnackBarThemeData.behavior of ThemeData.snackBarTheme is used. If that is null, then the default is SnackBarBehavior.fixed.
Implementation
final SnackBarBehavior? behavior;