void SNC_io_parser<EW>::print_volume(Volume_handle c) const
{ // syntax: index { shlist } mark
  out << index(c) << " { ";
  Shell_entry_iterator it;
  CGAL_forall_shells_of(it,c)
    if(!reduce || Infi_box::is_standard(SFace_handle(it)->center_vertex()->point()))
      out << index(SFace_handle(it)) << ' ';
  out << "} " << c->mark() << std::endl;
}
void SNC_io_parser<EW>::print_volume(Volume_handle c) const
{  
  out << index(c) << " { ";
  Shell_entry_iterator it;
  CGAL_forall_shells_of(it,c)
    if(!reduce || Infi_box::is_standard(SFace_handle(it)->center_vertex()->point()))
      out << index(SFace_handle(it)) << ' ';
  out << "} " << c->mark() << std::endl;
}