You can do a lot of things if you access the internal data structures that this package maintains, but this isn't supported and is likely to break in future releases as this package evolves. These structures just exist to support the public interfaces of the package, which is what you should use instead.

The design for rooms is that they are implicitly created and destroyed as needed, if really doesn't make sense to create a room or to check if a room exists. If you need to know what rooms are available, then you should track these rooms in your own application.