public class SimpleRateLimiter {

    private ExecutorService executorService = Executors.newFixedThreadPool(10);
    private static SimpleRateLimiter srl = new SimpleRateLimiter();

    private SimpleRateLimiter() {}

    public static SimpleRateLimiter getInstance() {
        return srl;
    }

    public void doSomething() {
        executorService.submit(new Runnable() {
            @Override
            public void run() {

                // call to 3rd party api
            }
        });
    }

    public void terminate() throws Exception {
        executorService.shutdown();
    }

}