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This is, of course, a bit of a problem. We don't have an avenue for ensuring that this ThreadLocal is destroyed
at the end of the request, and that means a thread can hold a reference to the class and the class loader which
loaded it. This may cause redeployment problems (leaked classes and class loaders). Apparently JDK 1.6 provides
the APIs to check to see if the current thread has a read lock. So, we tend to remove the TL, rather than set its
value to false.