Add a new country to countries list

/**
 * Add a new country to countries list
 */
add_filter( 'woocommerce_countries',  'handsome_bearded_guy_add_my_country' );
function handsome_bearded_guy_add_my_country( $countries ) {
  $new_countries = array(
                     'NIRE'  => __( 'Northern Ireland', 'woocommerce' ),
                     );
  return array_merge( $countries, $new_countries );
}
 add_filter( 'woocommerce_continents', 'handsome_bearded_guy_add_my_country_to_continents' );
function handsome_bearded_guy_add_my_country_to_continents( $continents ) {
 $continents['EU']['countries'][] = 'NIRE';
 return $continents;
}