The cruel reality is you cannot be sure. Maybe there is a typo in the config file and then the instance will not be created. The best thing is to actually treat the error. For example you can check for null: if (f != null) {furnishings.add(f);}
Exception handling is a very heated topic on the net. If you want you can also take a look at my article on the subject:
Exceptional Java - Thoughts on Java exceptions | Little Tutorials