public static void exportCHTsin(DelaunayTriangulation dto, String tsinFile) throws IOException {
   FileWriter fw = new FileWriter(tsinFile);
   PrintWriter os = new PrintWriter(fw);
   // prints the tsin file header:
   os.println(dto.getConvexHullSize());
   Iterator<Point> it = dto.getConvexHullVerticesIterator();
   while (it.hasNext()) {
     Point p = it.next();
     os.println(String.format("%s %s", p.getX(), p.getY()));
   }
   os.close();
   fw.close();
 }
 public static void exportTsin(DelaunayTriangulation dto, Writer writer) {
   PrintWriter os = new PrintWriter(writer);
   try {
     // prints the tsin file header:
     int len = dto.size();
     os.println(len);
     Iterator<Point> it = dto.verticesIterator();
     while (it.hasNext()) {
       Point p = it.next();
       os.println(String.format("%s %s %s", p.getX(), p.getY(), p.getZ()));
     }
   } finally {
     Utils.closeQuietly(os);
   }
 }