`NEXT.pm`

$self->NEXT::ACTUAL::method(...) will croak if there is no 'next' method

        sub AUTOLOAD {
          my ($self_class) = ref $_[0] || $_[0];
          my $cs = class_structure($self_class);

          my $caller_class = caller;
          my $next_class = $caller_class;

          my ($my_class, $method) = 
                ($NEXT::AUTOLOAD =~ /(.*)::(.*)/);

          do {
            $next_class = $cs->{$next_class};
          } while defined $next_class 
               && not defined &{"$next_class\::$method"} ;

          if (defined $next_class) {
            goto &{"$next_class\::$method"};
          } else {
            croak qq{Can't locate object method "$meth" 
                          via package "$self_class"};
              if $my_class eq 'NEXT::ACTUAL';
            return;        
          }
        }

        @NEXT::ACTUAL::ISA = ('NEXT');