/**
  * getConfiguration() method set all constant module in ps_configuration
  *
  * @param int $iShopId
  */
 public static function getConfiguration($iShopId = null)
 {
     // get configuration options
     if (null !== $iShopId && is_numeric($iShopId)) {
         FacebookPsConnect::$aConfiguration = Configuration::getMultiple(array_keys($GLOBALS[_FPC_MODULE_NAME . '_CONFIGURATION']), null, null, $iShopId);
     } else {
         FacebookPsConnect::$aConfiguration = Configuration::getMultiple(array_keys($GLOBALS[_FPC_MODULE_NAME . '_CONFIGURATION']));
     }
 }