message: Code review: let's use override as a good practice
diff: @@ -63,13 +63,13 @@ class Exact_Alphacomplex_dD : public Abstract_alpha_complex {
  alpha_complex_(boost::adaptors::transform(points, pt_cython_to_cgal<Point>)) {
  }
  - std::vector<double> get_point(int vh) override {
  + virtual std::vector<double> get_point(int vh) override {
  Point const& point = alpha_complex_.get_point(vh);
  return pt_cgal_to_cython(point);
  }
  - bool create_simplex_tree(Simplex_tree_interface<>* simplex_tree, double max_alpha_square,
  - bool default_filtration_value){
  + virtual bool create_simplex_tree(Simplex_tree_interface<>* simplex_tree, double max_alpha_square,
  + bool default_filtration_value) override {
  return alpha_complex_.create_complex(*simplex_tree, max_alpha_square, exact_version_, default_filtration_value);
  }
  @@ -89,12 +89,12 @@ class Inexact_Alphacomplex_dD : public Abstract_alpha_complex {
  alpha_complex_(boost::adaptors::transform(points, pt_cython_to_cgal<Point>)) {
  }
  - std::vector<double> get_point(int vh) {
  + virtual std::vector<double> get_point(int vh) override {
  Point const& point = alpha_complex_.get_point(vh);
  return pt_cgal_to_cython(point);
  }
  - bool create_simplex_tree(Simplex_tree_interface<>* simplex_tree, double max_alpha_square,
  - bool default_filtration_value){
  + virtual bool create_simplex_tree(Simplex_tree_interface<>* simplex_tree, double max_alpha_square,
  + bool default_filtration_value) override {
  return alpha_complex_.create_complex(*simplex_tree, max_alpha_square, exact_version_, default_filtration_value);
  }
  @@ -117,13 +117,13 @@ class Alphacomplex_3D : public Abstract_alpha_complex {
  : alpha_complex_(boost::adaptors::transform(points, pt_cython_to_cgal_3)) {
  }
  - std::vector<double> get_point(int vh) {
  + virtual std::vector<double> get_point(int vh) override {
  Point const& point = alpha_complex_.get_point(vh);
  return pt_cgal_to_cython(point);
  }
  - bool create_simplex_tree(Simplex_tree_interface<>* simplex_tree, double max_alpha_square,
  - bool default_filtration_value){
  + virtual bool create_simplex_tree(Simplex_tree_interface<>* simplex_tree, double max_alpha_square,
  + bool default_filtration_value) override {
  return alpha_complex_.create_complex(*simplex_tree, max_alpha_square);
  }
  