Method _getAssetName

/**
 * Method to compute the default name of the asset.
 * The default name is in the form table_name.id
 * where id is the value of the primary key of the table.
 *
 * @return  string
 *
 * @since   1.6
 */
protected function _getAssetName()
{
    $k = $this->_tbl_key;
    return $this->extension . '.category.' . (int) $this->{$k};
}