anchor.diff:  
       foreach my $test_desc ( keys %normalized_scores )
       {
  -        foreach my $metric ( keys $normalized_scores{$test_desc} )
  +        foreach my $metric ( keys %{$normalized_scores{$test_desc} })
           {
               foreach my $device_id (
  -                keys $normalized_scores{$test_desc}{$metric} )
  +                keys %{ $normalized_scores{$test_desc}{$metric} })
               {
                   my @row_data = (
                       $device_id_to_display_name{$device_id},
  
positive.code: 
      foreach my $policy ( keys %weighted_score_components )
      {
          foreach my $test_desc ( keys $weighted_score_components{$policy} )
          {
              foreach my $metric (
                  keys $weighted_score_components{$policy}{$test_desc} )
              {
                  foreach my $device_id (
                      keys
                          $weighted_score_components
                          {$policy}
                          {$test_desc}
                          {$metric} )
                  {
                      my $weighted_score = 
                          $weighted_score_components
  
negative.code: 
      foreach my $test_desc ( keys %$href )
      {
          foreach my $metric ( keys %{ $href->{$test_desc} })
          {
              my $sense = get_column_sense( $metric );
  
              if( $sense =~ /smaller is better/ )
              {
                  foreach my $device_id ( keys % { $href->{$test_desc}{$metric} })
                  {
                      negate( $href->{$test_desc}{$metric}{$device_id} );
                  }
  