gistfile1.txt

 List<String> gpsInString = Arrays.asList("GPS_1","GPS_2","GPS_3","GPS_4","GPS_5","GPS_6","GPS_7","GPS_8","GPS_9");
        Observable.from(gpsInString).map(new Func1<String, Integer>() {
            @Override
            public Integer call(String s) {
                int coordinate = Character.getNumericValue(s.charAt(4));
                System.out.println("Converted "+s+" to "+coordinate);

                return coordinate;
            }
        }).flatMap(new Func1<Integer, Observable<Hotel>>() {
            //Example of flatmap, we have a list of coordinates now, but actually we want a list of locations close
            @Override
            public Observable<Hotel> call(Integer coordinate) {
                System.out.println("Fetching hotel for "+ coordinate);
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

                return Observable.just(new Hotel());
            }
        }).subscribeOn(Schedulers.computation()).toList().toBlocking().last();