Dart APIunself_componentUnRootSheetPagefullscreenDialog fullscreenDialog property Null safety bool fullscreenDialog final Implementation final bool fullscreenDialog; unself_component unself_component UnRootSheetPage<T> fullscreenDialog property UnRootSheetPage class Constructors UnRootSheetPage Properties arguments child fullscreenDialog hashCode key maintainState name restorationId runtimeType Methods canUpdate createRoute noSuchMethod toString Operators operator ==