Why is there an AddAutoIncrementChange class, but no DropAutoIncrementChange?

Hi,
I found a problem when dropping Primary Keys on MySQL where I get:

    Reason: liquibase.exception.DatabaseException: Error executing SQL ALTER TABLE `TEST_SCHEMA`.`SMALL_TBL` DROP PRIMARY KEY:           Caused By: Error executing SQL ALTER TABLE `TEST_SCHEMA`.`SMALL_TBL` DROP PRIMARY KEY:           Caused By: Incorrect table definition; there can be only one auto column and it must be defined as a key

So I think I can make it work by dropping the AUTO_INCREMENT first, then dropping the Primary Key; but when I looked at the Liquibase change classes I couldn’t find a DropAutoIncrementChange class.
Is there a reason why it doesn’t exist, or was it just forgotten?

Just forgotten/not gotten to.  For now, you’ll have to either use the tag, or write your own extension

Nathan