void getAndPrintLocation() {
    geofire.getLocation("Mechelen", new LocationCallBack(
            (String key, List<double> location) {
          print("Successfully received location!");
          print(key + ": " + location.toString());
        },
            (DatabaseError error) {
          print("Error receiving location!");
          print(error.toString());
        }
    ));
  }

  void createQuery(List<double> location, double radius) {
    this.query = geofire.queryAtLocation(location, radius);
    print(this.query.toString());
  }

I/flutter (18068): GeoQuery
I/flutter (18068): --- Center: [51.0259, 4.4775]
I/flutter (18068): --- Radius: 450.0