public FMUCMode getFmucOutboundMode() {
        return fmucOutboundMode;
    }
Returns the 'mode' that describes the FMUC configuration is captured in the supplied object, which is
either master-master or master-slave.

This method should return null only when no outbound federation should be attempted.

@return FMUC mode applied to outbound FMUC federation attempts.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java