/**
  * validates a single shipping band
  */
 private static function validate_shipping_band($band, $band_index, $default)
 {
     $details = array();
     if (isset($band["name_" . $band_index]) && trim($band["name_" . $band_index]) !== "" && isset($band["band_id_" . $band_index]) && trim($band["band_id_" . $band_index]) !== "") {
         $regions = parent::get_shipping_regions();
         foreach ($regions as $region_code => $region_data) {
             // get shorthand for array indexes
             $s1 = "shipping_one_" . $region_code . "_" . $band_index;
             $sm = "shipping_multiple_" . $region_code . "_" . $band_index;
             if (isset($band[$s1]) && trim($band[$s1]) !== "" && isset($band[$sm]) && trim($band[$sm]) !== "") {
                 $details[$region_code] = array();
                 $details[$region_code]["shipping_one"] = SimplePayPalPluginAdmin::dec2($band[$s1]);
                 $details[$region_code]["shipping_multiple"] = SimplePayPalPluginAdmin::dec2($band[$sm]);
             }
         }
         if (count($details)) {
             $details["name"] = trim($band["name_" . $band_index]);
             $details["band_id"] = $band["band_id_" . $band_index];
             $details["default"] = $default == $band_index ? 1 : 0;
             $details["additional_free"] = isset($band["additional_free_" . $band_index]) ? 1 : 0;
         }
     }
     return $details;
 }