Getting empty success with Geonames

Hi,

I'm having trouble debugging what went wrong with this Geonames API query, as I'm getting only an empty response object?

Here's output on psy shell (using Laravel's 'artisan tinker' -tool):

>>> $zip = new PragmaRX\ZipCode\ZipCode;
=> PragmaRX\ZipCode\ZipCode {#693
+"finder": PragmaRX\ZipCode\Support\Finder {#694
+"timer": PragmaRX\Support\Timer {#696},
+"result": PragmaRX\ZipCode\Support\Result {#697},
},
}
>>> $zip->setCountry('FI');
=> null
>>> $zip->setPreferredWebService('Geonames');
=> null
>>> $zip->setQueryParameter('geonames_username', 'xxxxxxx');
=> null
>>> $res = $zip->find('07420');
=> PragmaRX\ZipCode\Support\Result {#715}
>>> print_r($res->toArray());
Array
(
[success] =>
)