GetCommandMap.java

    private static Method getCommandMap;

    public static CommandMap getCommandMap(Server server) {
        try {
            if (getCommandMap == null) {
                getCommandMap = server.getClass().getDeclaredMethod("getCommandMap");
                getCommandMap.setAccessible(true);
            }
            return (CommandMap) getCommandMap.invoke(server);
        } catch (Exception exception) {
            throw new IllegalArgumentException(exception);
        }
    }