Dart APIunself_componentUnCardisSelected isSelected property Null safety bool isSelected final Implementation final bool isSelected; unself_component unself_component UnCard isSelected property UnCard class Constructors UnCard Properties body footer hashCode header isExpandable isSelected key onTap runtimeType Methods build createElement debugDescribeChildren debugFillProperties noSuchMethod toDiagnosticsNode toString toStringDeep toStringShallow toStringShort Operators operator ==