@Override
    public void printStackTrace(PrintStream ps) {
        super.printStackTrace(ps);
        if (nestedThrowable != null) {
            nestedThrowable.printStackTrace(ps);
        }
    }
The packet error to include in the stanza that will be sent to the sender of the stanza that got rejected.
xmppserver/src/main/java/org/jivesoftware/openfire/interceptor/PacketRejectedException.java