Thread safe?

[Eric Douglas]

I think this is what they mean by thread safe.  I seem to have a
concurrency issue.  If I call a transform using the Fop handler with a
PNGRenderer from 2 JVM sessions at or near the same time one crashes.
I haven't been able to reproduce the problem so far with the PDFRenderer
so either it doesn't have the issue or my timing is off on attempting to
use it in 2 sessions at once.