use Class::Prototyped;

   my $european = Class::Prototyped->new(
       language => 'English',
       food     => 'Europizza',
   );

   my $german = Class::Prototyped->new(
       'parent*' => $european,
       food      => 'Wiener Schnitzel',
   );

   my $bavarian = Class::Prototyped->new(
       'parent*' => $german,
   );

   print "Default language: ",
         $bavarian->language(), "\n";

   $bavarian->language("Bavarian");
   print "Explicitely set language: ",
         $bavarian->language(), "\n";

    print "Default food: ",
          $bavarian->food(), "\n";