code: public function listInvalidProperties()
      {
          $invalid_properties = array();
  
          if ($this->container['id'] === null) {
              $invalid_properties[] = "'id' can't be null";
          }
          if ($this->container['value'] === null) {
              $invalid_properties[] = "'value' can't be null";
          }
          if ($this->container['active'] === null) {
              $invalid_properties[] = "'active' can't be null";
          }
          if ($this->container['created_date'] === null) {
              $invalid_properties[] = "'created_date' can't be null";
          }
          return $invalid_properties;
      }
docs: show all the invalid properties with reasons.
  
  @return array invalid properties with reasons