private function installStockMvtReason()
 {
     require_once _PS_MODULE_DIR_ . 'erpillicopresta/classes/stock/ErpStockMvtReason.php';
     foreach ($this->stock_mvt_reason as $name => $mvt_param) {
         $stock_mvt_reason_increase = new ErpStockMvtReason();
         $stock_mvt_reason_increase->name = array();
         foreach (Language::getLanguages(false) as $language) {
             $iso_code = array_key_exists($language['iso_code'], $mvt_param['lang']) ? $language['iso_code'] : 'en';
             $stock_mvt_reason_increase->name[$language['id_lang']] = $mvt_param['lang'][$iso_code];
         }
         $stock_mvt_reason_increase->sign = $mvt_param['sign'];
         if (!$stock_mvt_reason_increase->add(true)) {
             $this->_errors[] = $this->l('Error while creating stock movement reason : ') . $name . ' ' . $this->l('Please try again or contact the customer service.');
         }
         if (isset($mvt_param['configuration_name'])) {
             Configuration::updateValue($mvt_param['configuration_name'], null);
         }
     }
     return true;
 }