NSAutoreleasePool in NSOperation main?

Question

The documentation for +[NSThread detachNewThreadSelector:toTarget:withObject:] says:

For non garbage-collected applications, the method aSelector is responsible for setting up an autorelease pool for the newly detached thread and freeing that pool before it exits.

My question is, do I need to create my own NSAutoreleasePool in my override of the -[NSOperation main] method, or is the creation of the NSAutoreleasePool handled by NSOperation?