sub traverse {
  my $element = $_[0] ;
  if (Scalar::Util::blessed (${element})) {
    if (go_ahead(${element})) {
      my @contents = ${element}->content_refs_list() ;
      print "Before: ", @{contents}, "\n\n" ;
      for my $child (@contents) {
        traverse (${${child}}) ;
        print "Middle: ", ${${child}}, "\n\n" ;
      }
      print "After: ", @{contents}, "\n\n" ;
    }
  }
  else {
    print "Processing a string: " ;
    ${element} = curly_quotes(${element}) ;
    print ${element}, "\n\n" ;
  }
}