polylang + booster currency switcher - switch automatically on language change

functions.php

//searched a lot for this, ended up coding it myself -- based on WOOCS and WPML.
add_filter('wp_head', function() {
	$lang = get_locale();
	switch ($lang)
	{
		case 'ro_RO':
			wcj_session_set( 'wcj-currency', 'RON' );
			break;
		case 'fr_FR':
			wcj_session_set( 'wcj-currency', 'EUR' );
			break;
		default:
			wcj_session_set( 'wcj-currency', 'RON' );
			break;
	}
});