message: Use read_persistence_diagram_from_file in this example
diff: */
  #define CGAL_HAS_THREADS
  +#define DEBUG_TRACES
  #include <gudhi/Bottleneck.h>
  +#include <gudhi/reader_utils.h>
  #include <iostream>
  #include <vector>
  #include <utility> // for pair
  #include <sstream>
  #include <string>
  -std::vector< std::pair<double, double> > read_diagram_from_file(const char* filename) {
  - std::ifstream in;
  - in.open(filename);
  - std::vector< std::pair<double, double> > result;
  - if (!in.is_open()) {
  - std::cerr << "File : " << filename << " do not exist. The program will now terminate \n";
  - throw "File do not exist \n";
  - }
  -
  - std::string line;
  - while (!in.eof()) {
  - getline(in, line);
  - if (line.length() != 0) {
  - std::stringstream lineSS;
  - lineSS << line;
  - double beginn, endd;
  - lineSS >> beginn;
  - lineSS >> endd;
  - result.push_back(std::make_pair(beginn, endd));
  - }
  - }
  - in.close();
  - return result;
  -} // read_diagram_from_file
  -
  int main(int argc, char** argv) {
  if (argc < 3) {
  std::cout << "To run this program please provide as an input two files with persistence diagrams. Each file " <<
  "should contain a birth-death pair per line. Third, optional parameter is an error bound on a bottleneck" <<
  " distance (set by default to zero). The program will now terminate \n";
  }
  - std::vector< std::pair< double, double > > diag1 = read_diagram_from_file(argv[1]);
  - std::vector< std::pair< double, double > > diag2 = read_diagram_from_file(argv[2]);
  + std::vector< std::pair< double, double > > diag1 = read_persistence_diagram_from_file(argv[1]);
  + std::vector< std::pair< double, double > > diag2 = read_persistence_diagram_from_file(argv[2]);
  double tolerance = 0.;
  if (argc == 4) {
  tolerance = atof(argv[3]);
  