// Copyright (c) 2020, 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.

/**
 * @assertion We say that a type T0 is a subtype of a type T1 (written T0 <: T1)
 * when:
 * Left Null: if T0 is Null then:
 * - if T1 is a type variable (promoted or not) the query is false
 * - If T1 is FutureOr<S> for some S, then the query is true iff Null <: S.
 * - If T1 is Null, S? or S* for some S, then the query is true.
 * - Otherwise, the query is false
 * @description Check that if type T0 is Null and If T1 is Null? then T0 is
 * subtype of T1
 * @author sgrekhov@unipro.ru
 */
/**
 * @description Check that if type T0 is a subtype of a type T1, then instance
 * of T0 can be be used as a return value of type T1
 * @author sgrekhov@unipro.ru
 */
/*
 * This test is generated from left_null_A04.dart and 
 * return_value_x01.dart.
 * Don't modify it. If you want to change this file, change one of the files 
 * above and then run generator.dart to regenerate the tests.
 */


Null t0Instance = null;
Null? t1Instance = null;

const t1Default = null;


Null? returnValueFunc() => t0Instance;

class ReturnValueTest {
  static Null? staticTestMethod() => t0Instance;

  Null? testMethod() => t0Instance;

  Null? get testGetter => t0Instance;
}

main() {
  Null? returnValueLocalFunc() => t0Instance;

  returnValueFunc();
  returnValueLocalFunc();

  ReturnValueTest.staticTestMethod();

  new ReturnValueTest().testMethod();
  new ReturnValueTest().testGetter;

}