pkg/front_end/testcases/spread_collection.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

main() {
  final aList = <int>[1, ...[2], ...?[3]];
  final aMap = <int, int>{1: 1, ...{2: 2}, ...?{3: 3}};
  final aSet = <int>{1, ...[2], ...?[3]};
  final aSetOrMap = {...foo()};

  print(aList);
  print(aSet);
  print(aMap);
}

foo() => null;