isColumnSerial example

else {
          $value = $entity->$field_name->$column_name ?? NULL;
        }
        if (!empty($definition->getSchema()['columns'][$column_name]['serialize'])) {
          $value = serialize($value);
        }

        // Do not set serial fields if we do not have a value. This supports all         // SQL database drivers.         // @see https://www.drupal.org/node/2279395         $value = SqlContentEntityStorageSchema::castValue($definition->getSchema()['columns'][$column_name], $value);
        $empty_serial = empty($value) && $this->isColumnSerial($table_name, $schema_name);
        // The user entity is a very special case where the ID field is a serial         // but we need to insert a row with an ID of 0 to represent the         // anonymous user.         // @todo https://drupal.org/i/3222123 implement a generic fix for all         // entity types.         $user_zero = $this->entityTypeId === 'user' && $value === 0;
        if (!$empty_serial || $user_zero) {
          $record->$schema_name = $value;
        }
      }
    }