public List<IQHandler> getIQHandlers() {
        List<IQHandler> answer = new ArrayList<>();
        for (Module module : modules.values()) {
            if (module instanceof IQHandler) {
                answer.add((IQHandler) module);
            }
        }
        return answer;
    }
Returns a list with all the modules registered with the server that inherit from IQHandler.

@return a list with all the modules registered with the server that inherit from IQHandler.
xmppserver/src/main/java/org/jivesoftware/openfire/XMPPServer.java