public function add_current_identifier_info(&$entity)
 {
     $entity['customer_identifier_types'] = $this->get_valid_types_ui_values();
     if ($customer_identifier_type = $this->get_current_identifier_type($entity)) {
         $entity['customer_identifier_label'] = booking_uicommon::humanize($customer_identifier_type);
     }
     if ($customer_identifier_value = $this->get_current_identifier_value($entity)) {
         $entity['customer_identifier_value'] = $customer_identifier_value;
     }
 }