retaining references to Type objects between calls to process.

[Philip Ogren]

In the tutorial there is a section titled "Retaining references to JCas 
objects between calls to process()" which tells you not to retain 
references to JCas objects.  Is this also true for Type objects?  My 
guess is that it is fine to hold a reference between calls to process() 
so long as you are not changing the type system (and I'm not certain 
that it would be a problem then.)  It doesn't seem that TypeImpl knows 
anything about the CAS or the JCas and so holding a reference should be 
safe.  Is this correct?

Thanks,
Philip