pkg/front_end/testcases/extension_types/spread.dart.textual_outline.expect

extension type MyList<T>(List<T> it) implements List<T> {}

extension type MySet<T>(Set<T> it) implements Set<T> {}

extension type MyMap<K, V>(Map<K, V> it) implements Map<K, V> {}

method(MyList<int> list, MySet<String> set, MyMap<bool, num> map) {}

test() {}