protected function addAddress($address, $label, $field)
    {
        $label = is_string($label) ? trim($label) : $label;
        $address = is_string($address) ? trim($address) : $label;

        $label = $label ?: $address;

        if (!empty($address)) {
            $this->{$field}[$address] = $label;
        }
    }