Dart APIunself_componentUnSheetenableDrag enableDrag property Null safety bool enableDrag final Implementation final bool enableDrag; unself_component unself_component UnSheet<T> enableDrag property UnSheet class Constructors UnSheet Properties animationCurve arguments backgroundColor barrierColor bounce child clipBehavior closeProgressThreshold duration elevation enableDrag expand hashCode isDismissible key name overlayStyle previousRouteAnimationCurve restorationId runtimeType secondAnimation settings shadow shape topRadius transitionBackgroundColor useRootNavigator Methods canUpdate createRoute noSuchMethod toString Operators operator ==