Register with manager in order to get notifications that an instance is destroyed.
The message layer might have its own asynchronous notification protocol and this allows those mechanisms to be triggered.
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for (int i = 0; i < this.destructionListeners.size(); i++) { try { final DestructionCallback dc = (DestructionCallback) this.destructionListeners.get(i); if (dc != null) { dc.destroyed(); } } catch (Throwable t) { final String err = "Problem with asynchronous " + "destruction notification: " + t.getMessage();