Is called before XCloseListener::notifyClosing().
Listener has the chance to break that by throwing a CloseVetoException.
This exception must be passed to the original caller of XCloseable::close()
without any interaction.
The parameter GetsOwnership regulate who has to try to close the listened object
again, if this listener disagree with the request by throwing the exception.
If it's set to false the original caller of XCloseable::close()
will be the owner in every case. It's not allowed to call close() from this listener then.
If it's set to true this listener will be the new owner if he throw the exception,
otherwise not! If his still running processes will be finished he must call close() on
listened object again then.
If this listener doesn't disagree with th close request it depends from his internal
implementation if he deregister himself at the listened object.
But normaly this must be done in XCloseListener::notifyClosing().