anchor.diff:          'data': {
             'request': {'jsonrpc': '2.0', 'method': 'foo', 'id': 1234},
             'full': 'FormatException: bad format',
  -          'stack': contains('server_test.dart')
  +          'stack': new isInstanceOf<String>()
           }
         }
       }));
  
positive.code:           'data': {
              'request': {'jsonrpc': '2.0', 'method': 'foo', 'id': 1234},
              'full': 'FormatException: bad format',
              'stack': contains('server_test.dart')
            }
          }
        }));
  
negative.code:     });
  
      test("a JSON parse error is rejected", () {
        return server.parseRequest('invalid json {').then((result) {
          expect(JSON.decode(result), {
            'jsonrpc': '2.0',
            'error': {
              'code': error_code.PARSE_ERROR,
              'message': startsWith("Invalid JSON: "),
              'data': {'request': 'invalid json {'}
            },
            'id': null
          });
        });
      });
    });
  
  