Dart APIsettings_listSettingsListPagetrailing trailing property Null safety Widget? trailing final Implementation final Widget? trailing; unself_settings_list settings_list SettingsListPage trailing property SettingsListPage class Constructors SettingsListPage Properties hashCode key onSelectAppearance onSelectData onSelectFeedback onSelectLicense onSelectPrivacy onSelectTerms runtimeType trailing Methods build createElement debugDescribeChildren debugFillProperties noSuchMethod toDiagnosticsNode toString toStringDeep toStringShallow toStringShort Operators operator ==