cqengine: is the maven dependency on sqllite necessary?

I am using cqengine with no particular setting and I have a 6MB maven dependency on sqllite.

I currently just use NavigableIndexes, so I am not writing anything on my disk, not explicitely that is, however I'm managing very big lists.

My question is: can I remove this dependency? Or cqengine, behind the scenes, actually makes use of it when RAM is not enough?