anchor.diff:          var k = Key('t');
           MyClass c = MyClass(0);
           int p = 1;
  +        const t = 1;
   
           /* evaluation placeholder */
  -        print('\$c, \$k');
  +        print('\$c, \$k, \$t');
         }
         ''';
   
  
positive.code:           ''');
      });
  
      test('evaluate const expression', () async {
        await driver.check(
            scope: <String, String>{'p': '1'},
            expression: 'const MyClass(1)',
  
negative.code:           ''');
      });
  
      test('evaluate optimized const expression', () async {
        await driver.check(
            scope: <String, String>{},
            expression: 't',
            expectedResult: '''
            (function() {
              return 1;
            }(
            ))
            ''');
      },
          skip:
              'Cannot compile constants optimized away by the frontend'); // https://github.com/dart-lang/sdk/issues/41999
  
      test('evaluate factory constructor call', () async {
        await driver.check(
            scope: <String, String>{'p': '1'},
  