Dart APIlicense_detailLicenseDetailSliverpackageName packageName property Null safety String packageName final Implementation final String packageName; unself_license_detail license_detail LicenseDetailSliver packageName property LicenseDetailSliver class Constructors LicenseDetailSliver Properties hashCode key packageName runtimeType Methods build createElement debugDescribeChildren debugFillProperties noSuchMethod toDiagnosticsNode toString toStringDeep toStringShallow toStringShort Operators operator ==