Dart APIsettings_listSettingsListPageonSelectTerms onSelectTerms property Null safety VoidCallback onSelectTerms final Implementation final VoidCallback onSelectTerms; unself_settings_list settings_list SettingsListPage onSelectTerms 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 ==