# this is part of the actions-dispatch of my wiki-project

   'debug'  => sub {
      use MIME::Base64;
      use GraphViz::Data::Grapher;
      my $debug_wiki;
      while (my ($k, $v) = each %$wiki) {
         $debug_wiki->{$k} = substr($v, 0, 20).' ...';
      }
      my $graph = GraphViz::Data::Grapher->new($debug_wiki);
      return $q->header(), $q->start_html('DEBUG'), 
      '<IMG SRC="data:image/png;base64,', 
      encode_base64($graph->as_png),
      '" alt="debug"/>', $q->end_html;
   },