SingleObservable.java

            Single.create(new SingleOnSubscribe<User>() {
                    @Override
                    public void subscribe(SingleEmitter<User> emitter) throws Exception {
                        User user = new User("Anitaa");
                        emitter.onSuccess(user);
                    }
                })
                .observeOn(Schedulers.io())
                .subscribe(new SingleObserver<User>() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onSuccess(User user) {
                        System.out.println(String.format("User with name %s successfully created: ", user.getName()));
                    }

                    @Override
                    public void onError(Throwable e) {

                    }
                });