public void setRolesToBroadcastPresence(@Nonnull final List<Role> rolesToBroadcastPresence) {
        // TODO If the list changes while there are occupants in the room we must send available or
        // unavailable presences of the affected occupants to the rest of the occupants
        this.rolesToBroadcastPresence = rolesToBroadcastPresence;
    }
Sets the list of roles of which presence will be broadcast to the rest of the occupants.
This feature is useful for implementing "invisible" occupants.

@param rolesToBroadcastPresence the list of roles of which presence will be broadcast to
the rest of the occupants.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoom.java