| // Copyright (c) 2019, the R8 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. | 
 |  | 
 | package backport; | 
 |  | 
 | import java.util.OptionalDouble; | 
 |  | 
 | public final class OptionalDoubleBackportJava11Main { | 
 |  | 
 |   public static void main(String[] args) { | 
 |     testIsEmpty(); | 
 |   } | 
 |  | 
 |   private static void testIsEmpty() { | 
 |     OptionalDouble present = OptionalDouble.of(2d); | 
 |     assertFalse(present.isEmpty()); | 
 |  | 
 |     OptionalDouble absent = OptionalDouble.empty(); | 
 |     assertTrue(absent.isEmpty()); | 
 |   } | 
 |  | 
 |   private static void assertTrue(boolean value) { | 
 |     if (!value) { | 
 |       throw new AssertionError("Expected <true> but was <false>"); | 
 |     } | 
 |   } | 
 |  | 
 |   private static void assertFalse(boolean value) { | 
 |     if (value) { | 
 |       throw new AssertionError("Expected <false> but was <true>"); | 
 |     } | 
 |   } | 
 | } |