Is it safe to call Communicator.destroy() multiple times?

Have a look at:

http://www.zeroc.com/doc/Ice-3.4.0/reference/Ice/Communicator.html#destroy

"Destroy the communicator. This operation calls shutdown implicitly. Calling destroy cleans up memory, and shuts down this communicator's client functionality and destroys all object adapters. Subsequent calls to destroy are ignored."