With Kohana 3, how can I get the last insert ID from the Database class?

I have been through a fair bit of the code in modules/datab开发者_运维技巧ase/classes/ but still have not found how to return the last insert Id.

How do I get this?

query() method returns an array contains last inset id and number of rows affected

the actual code located at lines 201-208 at mysql.php (kohana v3.0.3)