// this is how you run a "data returning method"  asynchronously:
        // will query for data on a side thread, AND THEN return the results on main thread         
        // this.ioExecuterService = Executors.newSingleThreadExecutor();
        try {
            return ioExecuterService.submit(new Callable<Tea>() {
                @Override
                public Tea call() throws Exception {
                    return dao.getRandomTea();
                }
            }).get();
        } catch (InterruptedException | ExecutionException e) {
            e.printStackTrace();
            return null;
        }