/**
  * Transfer settings from old option fields to new system based on WC Settings API
  *
  * @since 4.4
  */
 private static function maybe_update_settings()
 {
     // Delete deprecated "wootax_shipping_taxable" option if it still exists
     if (get_option('wootax_shipping_taxable')) {
         delete_option('wootax_shipping_taxable');
     }
     // Transfer settings so they can be used with WooCommerce settings API
     $options = array('tc_id', 'tc_key', 'usps_id', 'show_exempt', 'exemption_text', 'company_name', 'show_zero_tax', 'tax_based_on', 'addresses', 'default_address');
     foreach ($options as $option) {
         if (get_option('wootax_' . $option)) {
             WC_WooTax::set_option($option, get_option('wootax_' . $option));
             delete_option('wootax_' . $option);
         }
     }
     // wootax_license_key option was deprecated in 4.5; remove it
     if (get_option('wootax_license_key')) {
         delete_option('wootax_license_key');
     }
 }