@Override
    public boolean isSharingSupported() {
        return true;
    }
Checks if any shared groups exists. No distinction is made between the type of shared group: any group that is
shared (with anything other than 'nobody') qualifies.

@return true if at least one shared group exists, otherwise false.
xmppserver/src/main/java/org/jivesoftware/openfire/group/AbstractGroupProvider.java