public function getList($countryIso, $optionalArgs = [])
    {
        $response = $this->client->fetch(
            $this->uri,
            array_merge(['country_iso'=>$countryIso], $optionalArgs)
        );

        $phoneNumbers = [];

        foreach ($response->getContent()['objects'] as $phoneNumber) {
            $newNumber = new PhoneNumber(
                $this->client, $phoneNumber, $this->pathParams['authId']);

            array_push($phoneNumbers, $newNumber);
        }
        return new ResourceList($this->client, $response->getContent()['meta'], $phoneNumbers);
    }