public function destroy_token($tokenId) {
		try {
			$sql = "DELETE FROM ". $this->table ." WHERE auth_token_id=:tokenId";
			$deleteRes = $this->db->run_update($sql, array('tokenId'=>$tokenId));
		}
		catch(exception $e) {
			throw new exception(__METHOD__ .": failed to destroy token::: ". $e->getMessage());
		}
		
		return($deleteRes);
	}