public OutboundJoinConfiguration getConfiguration() {
            return new OutboundJoinConfiguration(getPeer(), getMode() );
        }
A list of stanzas that need to have been echo'd by a remote FMUC node, before they can be processed locally.
This collection _does not_ include stanzas needed to set up the initial join. This collection is only used
for subsequent stanzas that are shared in a setting where echo-ing is required (due to the mode of the
federation being defined as 'master-slave').
xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/FMUCHandler.java