public boolean hasChangedSubject() {
        return historyStrategy.hasChangedSubject();
    }
Returns true if there is a message within the history of the room that has changed the
room's subject.

@return true if there is a message within the history of the room that has changed the
        room's subject.
xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoomHistory.java