Testing DB2 Timestamp function in H2

I'm trying to make unit tests work in H2 for the DB2 function TIMESTAMP(Date, int) which sets the precision for the timestamp.

A similar question led me to http://ift.tt/1G7DOGF but I'm not sure how the overloading would work in this scenario.

Can anyone give me an example?

( Also, please don't answer just to say that having different databases for testing and production is bad practice. It's not something I'll be able to change :/ )