public function filterCountry($country = 'US')
    {
        return $this->filter(
            function ($key, $value) use ($country) {
                if ($value instanceof CountryFilter && $value->getIso31661() == $country) {
                    return true;
                }
            }
        );
    }
public function filterCountry($country = 'US')
    {
        return $this->filter(
            function ($key, $value) use ($country) {
                if ($value instanceof CountryFilter && $value->getIso31661() == $country) {
                    return true;
                }
            }
        );
    }
public function filterCountry ( $ country = 'US' ) { return $ this -> filter ( function ( $ key , $ value ) use ( $ country ) { if ( $ value instanceof CountryFilter && $ value -> getIso31661 ( ) == $ country ) { return true ; } } ) ; }
Filter by country ISO 3166-1 code.

@param  string            $country
@return GenericCollection
Filter by country ISO 3166 - 1 code .