How to unlock / release files?

General Discussion
1

I’m trying to use Liquibase programmatically, but I’m running into an issue with file locks.  It seems like Liquibase is keeping the changelog files open after it’s done using them, and I can’t figure out how to close them.  I did some searching around on the internet and couldn’t find anything.  I assume this means the fix is really simple and easy and obvious, and I must be just missing it.  So how do I make Liquibase release filelocks when running changelog sets programmatically?