Dart APIunself_local_databaseCollectionDatadeleteRule deleteRule property Null safety String? deleteRule final Implementation final String? deleteRule; unself_local_database unself_local_database CollectionData deleteRule property CollectionData class Constructors CollectionData fromJson Properties created createRule deleteRule extra hashCode id listRule name runtimeType system type updated updateRule viewRule Methods copyWith noSuchMethod toColumns toCompanion toJson toJsonString toString Operators operator ==