RxJava groupBy example

public class MainActivity extends AppCompatActivity {

    public static class Shop {
        public int id;
        public String name;
        public List<Coordinate> coordinates = new ArrayList<>();

        @Override
        public String toString() {
            String str = id + " (" + name + ") [ ";
            for (Coordinate coordinate : coordinates) {
                str += (coordinate.toString() + " ");
            }
            str += "]";
            return str;
        }
    }

    public static class Coordinate {
        public String latitude;
        public String longitude;

        public Coordinate(String latitude, String longitude) {
            this.latitude = latitude;
            this.longitude = longitude;
        }

        @Override
        public String toString() {
            return "{" + latitude + ", " + longitude + "}";
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String[] cursor1row = {"1", "Foo", "lat1-1", "long1-1"};
        String[] cursor2row = {"1", "Foo", "lat1-2", "long1-2"};
        String[] cursor3row = {"2", "Bar", "lat2-1", "long2-1"};
        String[] cursor4row = {"1", "Foo", "lat1-3", "long1-3"};
        String[] cursor5row = {"1", "Foo", "lat1-4", "long1-4"};
        String[] cursor6row = {"3", "Ping", "lat3-1", "long3-1"};
        String[] cursor7row = {"2", "Bar", "lat2-2", "long2-2"};

        List<String[]> cursor = Arrays.asList(cursor1row, cursor2row, cursor3row, cursor4row, cursor5row, cursor6row, cursor7row);

        Observable.from(cursor)
                .groupBy(cursorRow -> cursorRow[0])
                .flatMap(groups -> groups.collect(Shop::new, (shop, rows) -> {
                    shop.id = Integer.parseInt(rows[0]);
                    shop.name = rows[1];
                    shop.coordinates.add(new Coordinate(rows[2], rows[3]));
                }))
                .subscribe(shop -> Log.d("RX", shop.toString()));
    }
}