if(log.isDebugEnabled()) log.debug(local_addr + " became coordinator");
    public void becomeCoordinator() {        CoordGmsImpl tmp=(CoordGmsImpl)impls.get(COORD);        if(tmp == null) {            tmp=new CoordGmsImpl(this);            impls.put(COORD, tmp);        }        tmp.leaving=false;        setImpl(tmp);         if(log.isDebugEnabled()) log.debug(local_addr + " became coordinator");    }