I'm currently using Lucene wrapped by an EJB and am investigating how it
behaves in that multi-threaded environment. I'm looking at adding LIUS,
but is it thread-safe? Also, I notice in the sample code that there are
several calls to getSingletonInstance(). Assuming LIUS is thread safe
and my app server has multiple instances of the EJB running, will LIUS
convert/index multiple documents at once or are the threads processed
one at a time?