Woocommerce - Change order of checkout fields

// Change order of billing fields on checkout page.
// From: http://wordpress.stackexchange.com/a/78377
add_filter('woocommerce_checkout_fields', 'bdd_reorder_billing_fields', 15);
function bdd_reorder_billing_fields($fields) {
    $order = array(
        'billing_first_name',
        'billing_last_name',
        //'billing_company',
        'billing_address_1',
        'billing_email',
        'billing_address_2',
        'billing_phone',
        'billing_city',
        'billing_state',
        'billing_country',
        'billing_postcode',
    );
    foreach($order as $field)
    {
// TODO: Check that $field is in $fields before saving it.
        $ordered_fields[$field] = $fields['billing'][$field];
    }

    $fields['billing'] = $ordered_fields;

    $fields['billing']['billing_first_name']['class'] = array('form-row-first');
    $fields['billing']['billing_last_name']['class'] = array('form-row-last');
    $fields['billing']['billing_address_1']['class'] = array('form-row-first', 'address-field');
    $fields['billing']['billing_email']['class'] = array('form-row-last');
    $fields['billing']['billing_address_2']['class'] = array('form-row-first', 'address-field');
    $fields['billing']['billing_phone']['class'] = array('form-row-last');
    $fields['billing']['billing_city']['class'] = array('form-row-first', 'address-field');
    $fields['billing']['billing_state']['class'] = array('form-row-first', 'address-field');
    $fields['billing']['billing_country']['class'] = array('form-row-first');
    $fields['billing']['billing_postcode']['class'] = array('form-row-first', 'address-field');

//echo '<!-- FIELDS: '.var_export($fields, true). ' -->';

    return $fields;
}