getStatusCode not found in Exception Laravel 5.5

i'm using laravel 5.5 and i'm testing this package, however, one of your class has a error throwed by my editor at this line: https://github.com/esbenp/heimdal/blob/master/src/Formatters/HttpExceptionFormatter.php#L19

following this error, i figure out the problem, the Exception class has only one method called:
```
getCode();
```

also the `getHeaders()` too. same problem. not found.